Inbred maize line PHBBK

ABSTRACT

A novel inbred maize variety designated PHBBK and seed, plants and plant parts thereof. Methods for producing a maize plant that comprise crossing inbred maize variety PHBBK with another maize plant. Methods for producing a maize plant containing in its genetic material one or more traits introgressed into PHBBK through backcross conversion and/or transformation, and to the maize seed, plant and plant part produced thereby. Hybrid maize seed, plant or plant part produced by crossing the inbred variety PHBBK or a trait conversion of PHBBK with another maize variety. Inbred maize varieties derived from inbred maize variety PHBBK, methods for producing other inbred maize varieties derived from inbred maize variety PHBBK and the inbred maize varieties and their parts derived by the use of those methods.

FIELD OF THE INVENTION

This invention relates generally to the field of maize breeding,specifically relating to an inbred maize variety designated PHBBK.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine, in a single variety or hybrid,various desirable traits. For field crops, these traits may includeresistance to diseases and insects, resistance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination, stand establishment, growth rate,maturity, plant height and ear height, is important. Traditional plantbreeding is an important tool in developing new and improved commercialcrops.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred maizevariety, designated PHBBK and processes for making PHBBK. This inventionrelates to seed of inbred maize variety PHBBK, to the plants of inbredmaize variety PHBBK, to plant parts of inbred maize variety PHBBK, andto processes for making a maize plant that comprise crossing inbredmaize variety PHBBK with another maize plant. This invention alsorelates to processes for making a maize plant containing in its geneticmaterial one or more traits introgressed into PHBBK through backcrossconversion and/or transformation, and to the maize seed, plant and plantpart produced by such introgression. This invention further relates to ahybrid maize seed, plant or plant part produced by crossing the inbredvariety PHBBK or an introgressed trait conversion of PHBBK with anothermaize variety. This invention also relates to inbred maize varietiesderived from inbred maize variety PHBBK to processes for making otherinbred maize varieties derived from inbred maize variety PHBBK and tothe inbred maize varieties and their parts derived by the use of thoseprocesses.

DEFINITIONS Inbred Definitions

Certain definitions used in the specification are provided below. Alsoin the examples that follow, a number of terms are used herein. In orderto provide a clear and consistent understanding of the specification andclaims, including the scope to be given such terms, the followingdefinitions are provided. NOTE: ABS is in absolute terms and % MN ispercent of the mean for the experiments in which the inbred or hybridwas grown. PCT designates that the trait is calculated as a percentage.% NOT designates the percentage of plants that did not exhibit a trait.For example, STKLDG % NOT is the percentage of plants in a plot thatwere not stalk lodged. These designators will follow the descriptors todenote how the values are to be interpreted. Below are the descriptorsused in the data tables included herein.

ABIOTIC STRESS TOLERANCE: resistance to non-biological sources of stressconferred by traits such as nitrogen utilization efficiency, alterednitrogen responsiveness, drought resistance cold, and salt resistance

ABTSTK=ARTIFICIAL BRITTLE STALK. A count of the number of “snapped”plants per plot following machine snapping. A snapped plant has itsstalk completely snapped at a node between the base of the plant and thenode above the ear. Expressed as percent of plants that did not snap.

ALEURONE: A thin layer of cells just beneath the pericarp of the seed.

ALLELE. Any of one or more alternative forms of a genetic sequence. In adiploid cell or organism, the two alleles of a given sequence typicallyoccupy corresponding loci on a pair of homologous chromosomes.

ALTER. The utilization of up-regulation, down-regulation, or genesilencing.

ANTHESIS. The time of a flower's opening.

ANTHOCYANIN OF BRACE ROOTS: The degree of red coloration of the braceroots after exposure to sunlight taken at flowering. Brace rootanthocyanin is scored 1-5 where 1=no red color, 2=pink, 3=red, 4=darkred, and 5=purple.

ANTIOXIDANT. A chemical compound or substance that inhibits oxidation,including but not limited to tocopherol or tocotrienols.

ANT ROT=ANTHRACNOSE STALK ROT (Colletotrichum graminicola). A 1 to 9visual rating indicating the resistance to Anthracnose Stalk Rot. Ahigher score indicates a higher resistance. Data are collected only whensufficient selection pressure exists in the experiment measured.

BACKCROSSING. Process in which a breeder crosses a hybrid progenyvariety back to one of the parental genotypes one or more times.

BACKCROSS PROGENY. Progeny plants produced by crossing PHF3P plant partswith plant parts of another maize line that comprise a desired trait orlocus, selecting F1 progeny plants that comprise the desired trait orlocus, and crossing the selected F1 progeny plants with the PHF3P plants1 or more times to produce backcross progeny plants that comprise saidtrait or locus.

BAR GLUMES: (glume band) The presence or absence of horizontal lines atthe base of the glumes on tassel florets.

BARPLT=BARREN PLANTS. The percent of plants per plot that were notbarren (lack ears).

BORBMN=ARTIFICIAL BRITTLE STALK MEAN. The mean percent of plants not“snapped” in a plot following artificial selection pressure. A snappedplant has its stalk completely snapped at a node between the base of theplant and the node above the ear. Expressed as percent of plants thatdid not snap. A high number is good and indicates tolerance to brittlesnapping.

BRANCH ANGLE FROM CENTRAL SPIKE: The adaxial angle measured in degreeswith a protractor on the top primary lateral tassel branch at flowering.

BRENGMN=BRITTLE STALK ENERGY MEAN. The mean amount of energy per unitarea needed to artificially brittle snap a corn stalk. A high number isgood and indicates tolerance to brittle snapping.

BREEDING. The genetic manipulation of living organisms.

BREEDING CROSS. A cross to introduce new genetic material into a plantfor the development of a new variety. For example, one could cross plantA with plant B, wherein plant B would be genetically different fromplant A. After the breeding cross, the resulting F1 plants could then beselfed or sibbed for one, two, three or more times (F1, F2, F3, etc.)until a new inbred variety is developed. For clarification, such newinbred varieties would be within a pedigree distance of one breedingcross of plants A and B. The process described above would be referredto as one breeding cycle.

BRLPNE. Percent plants not root lodged following artificial selectionpressure, preflowering. A high number is good and indicates tolerance topreflowering root lodging.

BRLPNL. Percent plants not root lodged following artificial selectionpressure, during grain filling period. A high number is good andindicates tolerance to late season root lodging.

BRTSTK=BRITTLE STALKS. This is a measure of the stalk breakage near thetime of pollination, and is an indication of whether a hybrid or inbredwould snap or break near the time of flowering under severe winds. Dataare presented as percentage of plants that did not snap. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

CARBOHYDRATE. Organic compounds comprising carbon, oxygen and hydrogen,including sugars, starches and cellulose.

CELL. Cell as used herein includes a plant cell, whether isolated, intissue culture or incorporated in a plant or plant part.

CLDTST=COLD TEST. The percent of plants that germinate under cold testconditions.

CLN=CORN LETHAL NECROSIS. Synergistic interaction of maize chloroticmottle virus (MCMV) in combination with either maize dwarf mosaic virus(MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV). A 1 to 9 visualrating indicating the resistance to Corn Lethal Necrosis. A higher scoreindicates a higher resistance. Data are collected only when sufficientselection pressure exists in the experiment measured.

COMRST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual rating indicatingthe resistance to Common Rust. A higher score indicates a higherresistance. Data are collected only when sufficient selection pressureexists in the experiment measured.

COMMON SMUT (Ustilago maydis): A 1 to 9 visual rating indicating theresistance to Common Smut. A higher score indicates a higher resistance.Data is collected only when sufficient selection pressure exists in theexperiment measured.

CROSS POLLINATION. A plant is cross pollinated if the pollen comes froma flower on a different plant from a different family or variety. Crosspollination excludes sib and self pollination.

CROSSING. The combination of genetic material by traditional methodssuch as a breeding cross or backcross, but also including protoplastfusion and other molecular biology methods of combining genetic materialfrom two source

D/D=DRYDOWN. This represents the relative rate at which a hybrid willreach acceptable harvest moisture compared to other hybrids on a 1 to 9rating scale. A high score indicates a hybrid that dries relatively fastwhile a low score indicates a hybrid that dries slowly.

DIPERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodiamacrospora). A 1 to 9 visual rating indicating the resistance toDiplodia Ear Mold. A higher score indicates a higher resistance. Dataare collected only when sufficient selection pressure exists in theexperiment measured.

DIPLOID PLANT PART. Refers to a plant part or cell that has the samediploid genotype as PHF3P.

DIPROT=DIPLODIA STALK ROT SCORE. Score of stalk rot severity due toDiplodia (Diplodia maydis). Expressed as a 1 to 9 score with 9 beinghighly resistant. Data are collected only when sufficient selectionpressure exists in the experiment measured.

DRPEAR=DROPPED EARS. A measure of the number of dropped ears per plotand represents the percentage of plants that did not drop ears prior toharvest. Data are collected only when sufficient selection pressureexists in the experiment measured.

D/T=DROUGHT TOLERANCE. This represents a 1 to 9 rating for droughttolerance, and is based on data obtained under stress conditions. A highscore indicates good drought tolerance and a low score indicates poordrought tolerance. Data are collected only when sufficient selectionpressure exists in the experiment measured.

EARHT=EAR HEIGHT. The ear height is a measure from the ground to thehighest placed developed ear node attachment and is measured incentimeters.

EARMLD=GENERAL EAR MOLD. Visual rating (1 to 9 score) where a 1 is verysusceptible and a 9 is very resistant. This is based on overall ratingfor ear mold of mature ears without determining the specific moldorganism, and may not be predictive for a specific ear mold. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

EAR NODE: The node on the main stem that bears the top or primary ear.

EAR POSITION: The orientation of the primary ear 65 days after 50% silk.Ear position is scored as 1=upright, 2=horizontal, and 3=pendant(downward or drooping).

EAR SHANK LENGTH: The measurement of the structure from the butt of theprimary ear to the ear node on the main stem.

EARSZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher therating the larger the ear size.

EBTSTK=EARLY BRITTLE STALK. A count of the number of “snapped” plantsper plot following severe winds when the corn plant is experiencing veryrapid vegetative growth in the V5-V8 stage. Expressed as percent ofplants that did not snap. Data are collected only when sufficientselection pressure exists in the experiment measured.

ECB1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING (Ostrinianubilalis). A 1 to 9 visual rating indicating the resistance topreflowering leaf feeding by first generation European Corn Borer. Ahigher score indicates a higher resistance. Data are collected only whensufficient selection pressure exists in the experiment measured.

ECB2IT=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING(Ostrinia nubilalis). Average inches of tunneling per plant in thestalk. Data are collected only when sufficient selection pressure existsin the experiment measured.

ECB2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinia nubilalis). A 1to 9 visual rating indicating post flowering degree of stalk breakageand other evidence of feeding by second generation European Corn Borer.A higher score indicates a higher resistance. Data are collected onlywhen sufficient selection pressure exists in the experiment measured.

ECBDPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis). Droppedears due to European Corn Borer. Percentage of plants that did not dropears under second generation European Corn Borer infestation. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

ECBLSI=EUROPEAN CORN BORER LATE SEASON INTACT (Ostrinia nubilalis). A 1to 9 visual rating indicating late season intactness of the corn plantgiven damage (stalk breakage above and below the top ear) causedprimarily by 2^(nd) and/or 3^(rd) generation ECB larval feeding beforeharvest. A higher score is good and indicates more intact plants. Dataare collected only when sufficient selection pressure exists in theexperiment measured.

EGRWTH=EARLY GROWTH. This is a measure of the relative height and sizeof a corn seedling at the 2-4 leaf stage of growth. This is a visualrating (1 to 9), with 1 being weak or slow growth, 5 being averagegrowth and 9 being strong growth. Taller plants, wider leaves, moregreen mass and darker color constitute higher score. Data are collectedonly when sufficient selection pressure exists in the experimentmeasured.

ELITE INBRED. An inbred that contributed desirable qualities when usedto produce commercial hybrids. An elite inbred may also be used infurther breeding for the purpose of developing further improvedvarieties.

ENDOSPERM: The nutritive tissue (starch) within the seed that surroundsthe embryo.

ERTLDG=EARLY ROOT LODGING. The percentage of plants that do not rootlodge prior to or around anthesis; plants that lean from the verticalaxis at an approximately 30 degree angle or greater would be counted asroot lodged. Data are collected only when sufficient selection pressureexists in the experiment measured.

ERTLPN=EARLY ROOT LODGING. An estimate of the percentage of plants thatdo not root lodge prior to or around anthesis; plants that lean from thevertical axis at an approximately 30 degree angle or greater would beconsidered as root lodged. Data are collected only when sufficientselection pressure exists in the experiment measured.

ERTLSC=EARLY ROOT LODGING SCORE. Score for severity of plants that leanfrom a vertical axis at an approximate 30 degree angle or greater whichtypically results from strong winds prior to or around floweringrecorded within 2 weeks of a wind event. Expressed as a 1 to 9 scorewith 9 being no lodging. Data are collected only when sufficientselection pressure exists in the experiment measured.

ESSENTIAL AMINO ACIDS. Amino acids that cannot be synthesized de novo byan organism and therefore must be supplied in the diet.

ESTCNT=EARLY STAND COUNT. This is a measure of the stand establishmentin the spring and represents the number of plants that emerge on perplot basis for the inbred or hybrid.

EYESPT=EYE SPOT (Kabatiella zeae or Aureobasidium zeae). A 1 to 9 visualrating indicating the resistance to Eye Spot. A higher score indicates ahigher resistance. Data are collected only when sufficient selectionpressure exists in the experiment measured.

EXPRESSING. Having the genetic potential such that under the rightconditions, the phenotypic trait is present.

FATTY ACID. A carboxylic acid (or organic acid), often with a longaliphatic tail (long chains), either saturated or unsaturated.

F1 PROGENY. Progeny plants produced by crossing plant parts of maizevariety PHF3P with plant parts of another maize line.

FUSERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusariumsubglutinans). A 1 to 9 visual rating indicating the resistance toFusarium Ear Rot. A higher score indicates a higher resistance. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

GDU=GROWING DEGREE UNITS. Using the Barger Heat Unit Theory, whichassumes that maize growth occurs in the temperature range 50 degreesF.-86 degrees F. and that temperatures outside this range slow downgrowth; the maximum daily heat unit accumulation is 36 and the minimumdaily heat unit accumulation is 0. The seasonal accumulation of GDU is amajor factor in determining maturity zones.

GDUSHD=GDU TO SHED. The number of growing degree units (GDUs) or heatunits required for an inbred variety or hybrid to have approximately 50percent of the plants shedding pollen and is measured from the time ofplanting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are:

${GDU} = {\frac{\left( {{Max}.\mspace{14mu}{temp}.\;{+ \;{{Min}.\mspace{14mu}{temp}.}}} \right)}{2} - 50}$

The highest maximum temperature used is 86 degrees F. and the lowestminimum temperature used is 50 degrees F. For each inbred or hybrid ittakes a certain number of GDUs to reach various stages of plantdevelopment.

GDUSLK=GDU TO SILK. The number of growing degree units required for aninbred variety or hybrid to have approximately 50 percent of the plantswith silk emergence from time of planting. Growing degree units arecalculated by the Barger Method as given in GDU SHD definition.

GENE SILENCING. The interruption or suppression of the expression of agene at the level of transcription or translation.

GENOTYPE. Refers to the genetic constitution of a cell or organism.

GIBERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9 visualrating indicating the resistance to Gibberella Ear Rot. A higher scoreindicates a higher resistance. Data are collected only when sufficientselection pressure exists in the experiment measured.

GIBROT=GIBBERELLA STALK ROT SCORE. Score of stalk rot severity due toGibberella (Gibberella zeae). Expressed as a 1 to 9 score with 9 beinghighly resistant. Data are collected only when sufficient selectionpressure exists in the experiment measured.

GLFSPT=GRAY LEAF SPOT (Cercospora zeae-maydis). A 1 to 9 visual ratingindicating the resistance to Gray Leaf Spot. A higher score indicates ahigher resistance. Data are collected only when sufficient selectionpressure exists in the experiment measured.

GOSWLT=GOSS' WILT (Corynebacterium nebraskense). A 1 to 9 visual ratingindicating the resistance to Goss' Wilt. A higher score indicates ahigher resistance. Data are collected only when sufficient selectionpressure exists in the experiment measured.

GRNAPP=GRAIN APPEARANCE. This is a 1 to 9 rating for the generalappearance of the shelled grain as it is harvested based on such factorsas the color of harvested grain, any mold on the grain, and any crackedgrain. High scores indicate good grain visual quality.

HAPLOID PLANT PART. Refers to a plant part or cell that has the samehaploid genotype as PHF3P.

HCBLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporium carbonum).A 1 to 9 visual rating indicating the resistance to Helminthosporiuminfection. A higher score indicates a higher resistance. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

HD SMT=HEAD SMUT (Sphacelotheca reiliana). This score indicates thepercentage of plants not infected. Data are collected only whensufficient selection pressure exists in the experiment measured.

HSKCVR=HUSK COVER. A 1 to 9 score based on performance relative to keychecks, with a score of 1 indicating very short husks, tip of ear andkernels showing; 5 is intermediate coverage of the ear under mostconditions, sometimes with thin husk; and a 9 has husks extending andclosed beyond the tip of the ear. Scoring can best be done nearphysiological maturity stage or any time during dry down untilharvested.

HUSK EXTENSION: The distance the husk extends past the end of theprimary ear at harvest.

HUSK TIGHTNESS: The tightness of the husk 65 days after 50% silking on ascale from 1 (very loose) to 9 (very tight).

INBRED. A variety developed through inbreeding or doubled haploidy thatpreferably comprises homozygous alleles at about 95% or more of itsloci.

INC D/A=GROSS INCOME (DOLLARS PER ACRE). Relative income per acreassuming drying costs of two cents per point above 15.5 percent harvestmoisture and current market price per bushel.

INCOME/ACRE. Income advantage of hybrid to be patented over other hybridon per acre basis.

INC ADV=GROSS INCOME ADVANTAGE. Gross income advantage of variety #1over variety #2.

INTERNODE: The structure between two nodes on the main stem.

INTROGRESSION. The process of transferring genetic material from onegenotype to another.

KERUNT=KERNELS PER UNIT AREA (Acres or Hectares).

KERPOP=KERNEL POP SCORE. The visual 1-9 rating of the amount ofrupturing of the kernel pericarp at an early stage in grain fill. Ahigher score is good and indicates no popped (ruptured) kernels.

KER_WT=KERNEL NUMBER PER UNIT WEIGHT (Pounds or Kilograms). The numberof kernels in a specific measured weight; determined after removal ofextremely small and large kernels.

KSZDCD=KERNEL SIZE DISCARD. The percent of discard seed; calculated asthe sum of discarded tip kernels and extra large kernels.

LEAF ANGLE: The adaxial angle measured in degrees with a protractor onthe second leaf above the top ear at flowering.

LEAF SHEATH PUBESCENCE: The density of pubescence on the face of theleaf sheath at flowering. Leaf Sheath Pubescence is scored on a 1-9scale where 1=no pubescence (smooth) and 9=high level of pubescence(like peach fuzz).

LINKAGE. Refers to a phenomenon wherein alleles on the same chromosometend to segregate together more often than expected by chance if theirtransmission was independent.

LINKAGE DISEQUILIBRIUM. Refers to a phenomenon wherein alleles tend toremain together in linkage groups when segregating from parents tooffspring, with a greater frequency than expected from their individualfrequencies.

LOCUS. A specific location on a chromosome.

LOCUS CONVERSION. A locus conversion refers to plants within a varietythat have been modified in a manner that retains the overall genetics ofthe variety and further comprises at least one locus with a specificdesired trait, such as insect, disease or herbicide resistance.

L/POP=YIELD AT LOW DENSITY. Yield ability at relatively low plantdensities on a 1 to 9 relative system with a higher number indicatingthe hybrid responds well to low plant densities for yield relative toother hybrids. A 1, 5, and 9 would represent very poor, average, andvery good yield response, respectively, to low plant density.

LRTLDG=LATE ROOT LODGING. The percentage of plants that do not rootlodge after anthesis through harvest; plants that lean from the verticalaxis at an approximately 30 degree angle or greater would be counted asroot lodged. Data are collected only when sufficient selection pressureexists in the experiment measured.

LRTLPN=LATE ROOT LODGING. An estimate of the percentage of plants thatdo not root lodge after anthesis through harvest; plants that lean fromthe vertical axis at an approximately 30 degree angle or greater wouldbe considered as root lodged. Data are collected only when sufficientselection pressure exists in the experiment measured.

LRTLSC=LATE ROOT LODGING SCORE. Score for severity of plants that leanfrom a vertical axis at an approximate 30 degree angle or greater whichtypically results from strong winds after flowering. Recorded prior toharvest when a root-lodging event has occurred. This lodging results inplants that are leaned or “lodged” over at the base of the plant and donot straighten or “goose-neck” back to a vertical position. Expressed asa 1 to 9 score with 9 being no lodging. Data are collected only whensufficient selection pressure exists in the experiment measured.

MALE STERILITY. A male sterile plant is one which produces no viablepollen. Male sterility prevents self pollination and the pollination ofneighboring plants. These male sterile plants are therefore useful inhybrid plant production.

MDMCPX=MAIZE DWARF MOSAIC COMPLEX (MDMV=Maize Dwarf Mosaic Virus andMCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating theresistance to Maize Dwarf Mosaic Complex. A higher score indicates ahigher resistance. Data are collected only when sufficient selectionpressure exists in the experiment measured.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture ofthe grain at harvest.

MSTADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1 overvariety #2 as calculated by: MOISTURE of variety #2−MOISTURE of variety#1=MOISTURE ADVANTAGE of variety #1.

NEI DISTANCE. A quantitative measure of percent similarity between twovarieties. Nei's distance between varieties A and B can be defined as1-(2*number alleles in common/(number alleles in A+number alleles in B).For example, if varieties A and B are the same for 95 out of 100alleles, the Nei distance would be 0.05. If varieties A and B are thesame for 98 out of 100 alleles, the Nei distance would be 0.02. Freesoftware for calculating Nei distance is available on the internet atmultiple locations such as, for example, at:evolution.genetics.washington.edu/phylip.html. See Nei, Proc Natl AcadSci, 76:5269-5273 (1979) which is incorporated by reference for thispurpose.

NLFBLT=NORTHERN LEAF BLIGHT (Helminthosporium turcicum or Exserohilumturcicum). A 1 to 9 visual rating indicating the resistance to NorthernLeaf Blight. A higher score indicates a higher resistance. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

OILT=GRAIN OIL. Absolute value of oil content of the kernel as predictedby Near-infrared Transmittance and expressed as a percent of dry matter.

PEDIGREE DISTANCE. Relationship among generations based on theirancestral links as evidenced in pedigrees. May be measured by thedistance of the pedigree from a given starting point in the ancestry.

PEDUNCLE NODE: The node on the main stem that the tassel originatesfrom.

PERCENT IDENTITY. Percent identity as used herein refers to thecomparison of the homozygous alleles of two inbred varieties. Eachinbred plant will have the same allele (and therefore be homozygous) atalmost all of their loci. Percent identity is determined by comparing astatistically significant number of the homozygous alleles of two inbredvarieties. For example, a percent identity of 90% between inbred PH8JVand other inbred variety means that the two inbred varieties have thesame homozygous alleles at 90% of their loci.

PERCENT SIMILARITY. Percent similarity as used herein refers to thecomparison of the homozygous alleles of an inbred plant with anotherplant. The homozygous alleles of PHF3P are compared with the alleles ofa non-inbred plant, such as a hybrid, and if the allele of the inbredmatches at least one of the corresponding alleles from the hybrid thenthey are scored as similar. Percent similarity is determined bycomparing a statistically significant number of loci and recording thenumber of loci with similar alleles as a percentage. For example, apercent similarity of 90% between inbred PHF3P and a hybrid maize plantmeans that the inbred variety matches at least one of the hybrid allelesat 90% of the loci. In the case of a hybrid produced from PHF3P as themale or female parent, such hybrid will comprise two sets of alleles,one set of which will comprise substantially the same alleles as thehomozygous alleles of inbred variety PHF3P.

PLANT. As used herein, the term “plant” includes reference to animmature or mature whole plant, including a plant that has beendetasseled or from which seed or grain has been removed. Seed or embryothat will produce the plant is also considered to be the plant.

PLANT PARTS. As used herein, the term “plant parts” includes leaves,stems, roots, seed, grain, embryo, pollen, ovules, flowers, ears, cobs,husks, stalks, root tips, anthers, pericarp, silk, tissue, cells and thelike.

PLTHT=PLANT HEIGHT. This is a measure of the height of the plant fromthe ground to the tip of the tassel in centimeters.

POLPRD=POLLEN PRODUCTION SCORE. The estimated total amount of pollenproduced by tassels based on the number of tassel branches and thedensity of the spikelets.

POLSC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount ofpollen shed. The higher the score the more pollen shed.

POLWT=POLLEN WEIGHT. This is calculated by dry weight of tasselscollected as shedding commences minus dry weight from similar tasselsharvested after shedding is complete.

POP K/A=PLANT POPULATIONS. Measured as 1000's per acre.

POP ADV=PLANT POPULATION ADVANTAGE. The plant population advantage ofvariety #1 over variety #2 as calculated by PLANT POPULATION of variety#2−PLANT POPULATION of variety #1=PLANT POPULATION ADVANTAGE of variety#1.

PRM=PREDICTED RELATIVE MATURITY. This trait, predicted relativematurity, is based on the harvest moisture of the grain. The relativematurity rating is based on a known set of checks and utilizes standardlinear regression analyses and is also referred to as the ComparativeRelative Maturity Rating System that is similar to the MinnesotaRelative Maturity Rating System.

PRMSHD=A relative measure of the growing degree units (GDU) required toreach 50% pollen shed. Relative values are predicted values from thelinear regression of observed GDU's on relative maturity of commercialchecks.

PRIMARY LATERAL TASSEL BRANCH: A branch that originates off the mainaxis of the tassel with more than 2 florets.

PROT=GRAIN PROTEIN. Absolute value of protein content of the kernel aspredicted by Near-infrared Transmittance and expressed as a percent ofdry matter.

RESISTANCE. Synonymous with tolerance. The ability of a plant towithstand exposure to an insect, disease, herbicide or other condition.A resistant plant variety will have a level of resistance higher than acomparable wild-type variety.

RTLDG=ROOT LODGING. Root lodging is the percentage of plants that do notroot lodge; plants that lean from the vertical axis at an approximately30 degree angle or greater would be counted as root lodged. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

RTLADV=ROOT LODGING ADVANTAGE. The root lodging advantage of variety #1over variety #2. Data are collected only when sufficient selectionpressure exists in the experiment measured.

SCTGRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount ofscatter grain (lack of pollination or kernel abortion) on the ear. Thehigher the score the less scatter grain.

SDGVGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amountof vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

SEED. Fertilized and ripened ovule, consisting of the plant embryo,varying amounts of stored food material, and a protective outer seedcoat. Synonymous with grain.

SEL IND=SELECTION INDEX. The selection index gives a single measure ofthe hybrid's worth based on information for up to five traits. A maizebreeder may utilize his or her own set of traits for the selectionindex. One of the traits that is almost always included is yield. Theselection index data presented in the tables represent the mean valueaveraged across testing stations.

SELF POLLINATION. A plant is self-pollinated if pollen from one floweris transferred to the same or another flower of the same plant.

SIB POLLINATION. A plant is sib-pollinated when individuals within thesame family or variety are used for pollination.

SINGLE LOCUS CONVERSION TRAIT. A trait that can be introgressed into acorn variety through introgression and/or transformation of a singlelocus. Examples of such single locus traits include mutant genes,transgenes and native traits finely mapped to a single locus. One ormore single locus conversion traits may be introduced into a single cornvariety.

SITE SPECIFIC INTEGRATION: Genes that create a site for site specificDNA integration. This includes the introduction of FRT sites that may beused in the FLP/FRT system and/or Lox sites that may be used in theCre/Loxp system. For example, see Lyznik, et al., Site-SpecificRecombination for Genetic Engineering in Plants, Plant Cell Rep (2003)21:925-932 and WO 99/25821.

SLFBLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolarismaydis). A 1 to 9 visual rating indicating the resistance to SouthernLeaf Blight. A higher score indicates a higher resistance. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

SOURST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual ratingindicating the resistance to Southern Rust. A higher score indicates ahigher resistance. Data are collected only when sufficient selectionpressure exists in the experiment measured.

SPKDSC=SPIKLET DENSITY SCORE. The visual 1-9 rating of how densespikelets are on the middle tassel branches. A higher score indicateshigher spikelet density.

STAGRN=STAY GREEN. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

STDADV=STALK STANDING ADVANTAGE. The advantage of variety #1 overvariety #2 for the trait STKCNT.

STKCNT=NUMBER OF PLANTS. This is the final stand or number of plants perplot.

STKLDG=STALK LODGING REGULAR. This is the percentage of plants that didnot stalk lodge (stalk breakage) at regular harvest (when grain moistureis between about 20 and 30%) as measured by either natural lodging orpushing the stalks and determining the percentage of plants that breakbelow the ear. Data are collected only when sufficient selectionpressure exists in the experiment measured.

STKLDS=STALK LODGING SCORE. A plant is considered as stalk lodged if thestalk is broken or crimped between the ear and the ground. This can becaused by any or a combination of the following: strong winds late inthe season, disease pressure within the stalks, ECB damage orgenetically weak stalks. This trait should be taken just prior to or atharvest. Expressed on a 1 to 9 scale with 9 being no lodging. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

STLLPN=LATE STALK LODGING. This is the percent of plants that did notstalk lodge (stalk breakage or crimping) at or around late seasonharvest (when grain moisture is below 20%) as measured by either naturallodging or pushing the stalks and determining the percentage of plantsthat break or crimp below the ear. Data are collected only whensufficient selection pressure exists in the experiment measured.

STLPCN=STALK LODGING REGULAR. This is an estimate of the percentage ofplants that did not stalk lodge (stalk breakage) at regular harvest(when grain moisture is between about 20 and 30%) as measured by eithernatural lodging or pushing the stalks and determining the percentage ofplants that break below the ear. Data are collected only when sufficientselection pressure exists in the experiment measured.

STLTIP=STERILE TIPS SCORE. The visual 1 to 9 rating of the relative lackof glumes on the tassel central spike and branches. A higher scoreindicates less incidence of sterile tips or lack of glumes on thetassel.

STRT=GRAIN STARCH. Absolute value of starch content of the kernel aspredicted by Near-infrared Transmittance and expressed as a percent ofdry matter.

STWWLT=Stewart's Wilt (Erwinia stewartii). A 1 to 9 visual ratingindicating the resistance to Stewart's Wilt. A higher score indicates ahigher resistance. Data are collected only when sufficient selectionpressure exists in the experiment measured.

SSRs. Genetic markers based on polymorphisms in repeated nucleotidesequences, such as microsatellites. A marker system based on SSRs can behighly informative in linkage analysis relative to other marker systemsin that multiple alleles may be present.

TASBLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure thedegree of blasting (necrosis due to heat stress) of the tassel at thetime of flowering. A 1 would indicate a very high level of blasting attime of flowering, while a 9 would have no tassel blasting. Data arecollected only when sufficient selection pressure exists in theexperiment measured.

TASBRN=TASSEL BRANCH NUMBER. The number of tassel branches, with anthersoriginating from the central spike.

TASSZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate therelative size of the tassel. The higher the rating the larger thetassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams)just prior to pollen shed.

TEXEAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate therelative hardness (smoothness of crown) of mature grain. A 1 would bevery soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that couldpossibly shed pollen was taken. Data are given as a percentage oftillers: number of tillers per plot divided by number of plants perplot.

TSTWT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grainin pounds for a given volume (bushel).

TSWADV=TEST WEIGHT ADVANTAGE. The test weight advantage of variety #1over variety #2.

TOP EAR: The highest and primary seed bearing structure of the cornplant.

VARIETY. A substantially homozygous inbred line and minor geneticmodifications thereof that retain the overall genetics of the inbredline including but not limited to a locus conversion, a mutation, or asomoclonal variant.

WIN M %=PERCENT MOISTURE WINS.

WIN Y %=PERCENT YIELD WINS.

YIELD BU/A=YIELD (BUSHELS/ACRE). Yield of the grain at harvest by weightor volume (bushels) per unit area (acre) adjusted to 15% moisture.

YLDADV=YIELD ADVANTAGE. The yield advantage of variety #1 over variety#2 as calculated by: YIELD of variety #1−YIELD variety #2=YIELDADVANTAGE of variety #1.

YLDSC=YIELD SCORE. A 1 to 9 visual rating was used to give a relativerating for yield based on plot ear piles. The higher the rating thegreater visual yield appearance.

Definitions for Area of Adaptability

When referring to area of adaptability, such term is used to describethe location with the environmental conditions that would be well suitedfor this maize variety. Area of adaptability is based on a number offactors, for example: days to maturity, insect resistance, diseaseresistance, and drought resistance. Area of adaptability does notindicate that the maize variety will grow in every location within thearea of adaptability or that it will not grow outside the area.

Central Corn Belt: Iowa, Illinois, Indiana

Drylands: non-irrigated areas of North Dakota, South Dakota, Nebraska,Kansas, Colorado, and Oklahoma

Eastern U.S.: Ohio, Pennsylvania, Delaware, Maryland, Virginia, and WestVirginia

North central U.S.: Minnesota and Wisconsin

Northeast: Michigan, New York, Vermont, and Ontario and Quebec Canada

Northwest U.S.: North Dakota, South Dakota, Wyoming, Washington, Oregon,Montana, Utah, and Idaho

South central U.S.: Missouri, Tennessee, Kentucky, Arkansas

Southeast U.S.: North Carolina, South Carolina, Georgia, Florida,Alabama, Mississippi, and Louisiana

Southwest U.S.: Texas, Oklahoma, New Mexico, Arizona

Western U.S.: Nebraska, Kansas, Colorado, and California

Maritime Europe Northern France, Germany, Belgium, Netherlands andAustria

DETAILED DESCRIPTION OF THE INVENTION AND FURTHER EMBODIMENTS

All tables discussed in the Detailed Description of the Invention andFurther Embodiments section can found at the end of the section.

Morphological and Physiological Characteristics of PHBBK

Inbred maize variety PHBBK is a maize inbred that may be used as eithera male or female in the production of the first generation F1 maizehybrid.

The inbred has shown uniformity and stability within the limits ofenvironmental influence for all the traits as described in the VarietyDescription Information (Table 1, found at the end of the section). Theinbred has been self-pollinated and ear-rowed a sufficient number ofgenerations with careful attention paid to uniformity of plant type toensure the homozygosity and phenotypic stability necessary for use incommercial hybrid seed production. The variety has been increased bothby hand and in isolated fields with continued observation foruniformity. No variant traits have been observed or are expected inPHBBK.

Inbred maize variety PHBBK, being substantially homozygous, can bereproduced by planting seeds of the variety, growing the resulting maizeplants under self-pollinating or sib-pollinating conditions withadequate isolation, and harvesting the resulting seed using techniquesfamiliar to the agricultural arts.

Genotypic Characteristics of PHBBK

In addition to phenotypic observations, a plant can also be identifiedby its genotype. The genotype of a plant can be characterized through agenetic marker profile, which can identify plants of the same variety ora related variety, or be used to determine or validate a pedigree. TheSSR profile of Inbred PHBBK can be found in Table 2 at the end of thissection.

As a result of inbreeding, PHBBK is substantially homozygous. Thishomozygosity has been characterized at the loci shown in the markerprofile provided herein. An F1 hybrid made with PHBBK wouldsubstantially comprise the marker profile of PHBBK shown herein. This isbecause an F1 hybrid is the sum of its inbred parents, e.g., if oneinbred parent is homozygous for allele x at a particular locus, and theother inbred parent is homozygous for allele y at that locus, the F1hybrid will be x.y (heterozygous) at that locus. The profile cantherefore be used to identify hybrids comprising PHBBK as a parent,since such hybrids will comprise two sets of alleles, one set of whichwill be from PHBBK. The determination of the male set of alleles and thefemale set of alleles may be made by profiling the hybrid and thepericarp of the hybrid seed, which is composed of maternal parent cells.One way to obtain the paternal parent profile is to subtract thepericarp profile from the hybrid profile.

Subsequent generations of progeny produced by selection and breeding areexpected to be of genotype x (homozygous), y (homozygous), or x.y(heterozygous) for these locus positions. When the F1 plant is used toproduce an inbred, the resulting inbred should be either x or y for thatallele. In that regard, a unique allele or combination of alleles uniqueto that inbred can be used to identify progeny plants developed withPHBBK.

Therefore, in accordance with the above, an embodiment of this inventionis a PHBBK progeny maize plant or plant part that is a first generation(F1) hybrid maize plant comprising two sets of alleles, wherein one setof the alleles is the same as PHBBK at substantially all of the SSR locilisted in Table 2. A maize cell wherein one set of the alleles is thesame as PHBBK at substantially all of the SSR loci listed in Table 2 isalso an embodiment of the invention. This maize cell may be a part of ahybrid seed, plant or plant part produced by crossing PHBBK with anotherinbred maize plant.

Genetic marker profiles can be obtained by techniques such asRestriction Fragment Length Polymorphisms (RFLPs), Randomly AmplifiedPolymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction(AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence CharacterizedAmplified Regions (SCARs), Amplified Fragment Length Polymorphisms(AFLPs), Simple Sequence Repeats (SSRs) which are also referred to asMicrosatellites, and Single Nucleotide Polymorphisms (SNPs). Forexample, see Berry, Don et al., “Assessing Probability of Ancestry UsingSimple Sequence Repeat Profiles: Applications to Maize Hybrids andInbreds”, Genetics, 2002, 161:813-824, and Berry, Don et al., “AssessingProbability of Ancestry Using Simple Sequence Repeat Profiles:Applications to Maize Inbred Lines and Soybean Varieties”, Genetics,2003, 165: 331-342.

Particular markers used for these purposes are not limited to the set ofmarkers disclosed herein, but may include any type of marker and markerprofile which provides a means of distinguishing varieties. In additionto being used for identification of Inbred maize variety PHBBK, a hybridproduced through the use of PHBBK, and the identification orverification of pedigree for progeny plants produced through the use ofPHBBK, the genetic marker profile is also useful in developing anintrogressed trait conversion of PHBBK.

Means of performing genetic marker profiles using SSR polymorphisms arewell known in the art. SSRs are genetic markers based on polymorphismsin repeated nucleotide sequences, such as microsatellites. A markersystem based on SSRs can be highly informative in linkage analysisrelative to other marker systems in that multiple alleles may bepresent. Another advantage of this type of marker is that, through useof flanking primers, detection of SSRs can be achieved, for example, bythe polymerase chain reaction (PCR), thereby eliminating the need forlabor-intensive Southern hybridization. The PCR detection is done by useof two oligonucleotide primers flanking the polymorphic segment ofrepetitive DNA. Repeated cycles of heat denaturation of the DNA followedby annealing of the primers to their complementary sequences at lowtemperatures, and extension of the annealed primers with DNA polymerase,comprise the major part of the methodology.

Following amplification, markers can be scored by electrophoresis of theamplification products. Scoring of marker genotype is based on the sizeof the amplified fragment, which may be measured by the number of basepairs of the fragment. While variation in the primer used or inlaboratory procedures can affect the reported fragment size, relativevalues should remain constant regardless of the specific primer orlaboratory used. When comparing plants it is preferable if all SSRprofiles are performed in the same lab. The SSR analyses reported hereinwere conducted in-house at Pioneer Hi-Bred. An SSR service is availableto the public on a contractual basis by DNA Landmarks inSaint-Jean-sur-Richelieu, Quebec, Canada.

Primers used for the SSRs reported herein are publicly available and maybe found in the Maize GDB on the World Wide Web at maizegdb.org(sponsored by the USDA Agricultural Research Service), in Sharopova etal. (Plant Mol. Biol. 48(5-6):463-481), Lee et al. (Plant Mol. Biol.48(5-6); 453-461), or may be constructed from sequences if reportedherein. Primers may be constructed from publicly available sequenceinformation. Some marker information may also be available from DNALandmarks.

Map information is provided by chromosome position and location. Binnumbers corresponding to these loci are reported in the Maize GDB forthe IBM 2 and/or IBM 2 Neighbors maps. Map positions are also availableon the Maize GDB for a variety of different mapping populations.

PHBBK and its plant parts can be identified through a molecular markerprofile. An inbred corn plant cell having the SSR genetic marker profileshown in Table 2 is an embodiment of the invention. Such plant cell maybe either diploid or haploid.

Also encompassed within the scope of the invention are plants and plantparts substantially benefiting from the use of PHBBK in theirdevelopment, such as PHBBK comprising a introgressed trait throughbackcross conversion or transformation, and which may be identified byhaving an SSR molecular marker profile with a high percent identity toPHBBK, such as at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5% identity.Likewise, percent similarity at these percentages may be used toidentify plants produced by the use of PHBBK.

Comparing PHBBK to Other Inbreds

A breeder uses various methods to help determine which plants should beselected from segregating populations and ultimately which inbredvarieties will be used to develop hybrids for commercialization. Inaddition to knowledge of the germplasm and plant genetics, a part of theselection process is dependent on experimental design coupled with theuse of statistical analysis. Experimental design and statisticalanalysis are used to help determine which plants, which family ofplants, and finally which inbred varieties and hybrid combinations aresignificantly better or different for one or more traits of interest.Experimental design methods are used to assess error so that differencesbetween two inbred varieties or two hybrid varieties can be moreaccurately evaluated. Statistical analysis includes the calculation ofmean values, determination of the statistical significance of thesources of variation, and the calculation of the appropriate variancecomponents. Either a five or a one percent significance level iscustomarily used to determine whether a difference that occurs for agiven trait is real or due to the environment or experimental error. Oneof ordinary skill in the art of plant breeding would know how toevaluate the traits of two plant varieties to determine if there is nosignificant difference between the two traits expressed by thosevarieties. For example, see Fehr, Walt, Principles of CultivarDevelopment, p. 261-286 (1987). Mean trait values may be used todetermine whether trait differences are significant. Trait values shouldpreferably be measured on plants grown under the same environmentalconditions, and environmental conditions should be appropriate for thetraits or traits being evaluated. Sufficient selection pressure shouldbe present for optimum measurement of traits of interest such asherbicide, insect or disease resistance. A locus conversion of PHBBK forherbicide resistance should be compared with an isogenic counterpart inthe absence of the converted trait. In addition, a locus conversion forinsect or disease resistance should be compared to the isogeniccounterpart, in the absence of disease pressure or insect pressure.

The results in Table 3A compare inbred PHBBK to inbred PH7BW. Theresults show inbred PHBBK has significantly different moisture, tillercount and plant height when compared to PH7BW.

The results in Table 3B compare inbred PHBBK to inbred PH1W0. Theresults show inbred PHBBK differs significantly at growing degrees unitswhen compared to inbred PH1W0.

Development of Maize Hybrids using PHBBK

A single cross maize hybrid results from the cross of two inbredvarieties, each of which has a genotype that complements the genotype ofthe other. A hybrid progeny of the first generation is designated F1. Inthe development of commercial hybrids in a maize plant breeding program,only the F1 hybrid plants are sought. F1 hybrids are more vigorous thantheir inbred parents. This hybrid vigor, or heterosis, can be manifestedin many polygenic traits, including increased vegetative growth andincreased yield.

PHBBK may be used to produce hybrid maize. One such embodiment is themethod of crossing inbred maize variety PHBBK with another maize plant,such as a different maize inbred variety, to form a first generation F1hybrid seed. The first generation F1 hybrid seed, plant and plant partproduced by this method is an embodiment of the invention. The firstgeneration F1 seed, plant and plant part will comprise an essentiallycomplete set of the alleles of inbred variety PHBBK. One of ordinaryskill in the art can utilize either breeder books or molecular methodsto identify a particular F1 hybrid plant produced using inbred varietyPHBBK. Further, one of ordinary skill in the art may also produce F1hybrids with transgenic, male sterile and/or backcross conversions ofinbred variety PHBBK

The development of a maize hybrid in a maize plant breeding programinvolves three steps: (1) the selection of plants from various germplasmpools for initial breeding crosses; (2) the selfing of the selectedplants from the breeding crosses for several generations to produce aseries of inbred varieties, such as PHBBK, which, although differentfrom each other, breed true and are highly uniform; and (3) crossing theselected inbred varieties with different inbred varieties to produce thehybrids. During the inbreeding process in maize, the vigor of thevarieties decreases, and so one would not be likely to use PHBBKdirectly to produce grain. However, vigor is restored when PHBBK iscrossed to a different inbred variety to produce a commercial F1 hybrid.An important consequence of the homozygosity and homogeneity of theinbred variety is that the hybrid between a defined pair of inbreds maybe reproduced indefinitely as long as the homogeneity of the inbredparents is maintained.

PHBBK may be used to produce a single cross hybrid, a double crosshybrid, or a three-way hybrid. A single cross hybrid is produced whentwo inbred varieties are crossed to produce the F1 progeny. A doublecross hybrid is produced from four inbred varieties crossed in pairs(A×B and C×D) and then the two F1 hybrids are crossed again (A×B)×(C×D).A three-way cross hybrid is produced from three inbred varieties wheretwo of the inbred varieties are crossed (A×B) and then the resulting F1hybrid is crossed with the third inbred (A×B)×C. In each case, pericarptissue from the female parent will be a part of and protect the hybridseed.

Combining Ability of PHBBK

Combining ability of a variety, as well as the performance of thevariety per se, is a factor in the selection of improved maize inbreds.Combining ability refers to a variety's contribution as a parent whencrossed with other varieties to form hybrids. The hybrids formed for thepurpose of selecting superior varieties may be referred to as testcrosses, and include comparisons to other hybrid varieties grown in thesame environment (same cross, location and time of planting). One way ofmeasuring combining ability is by using values based in part on theoverall mean of a number of test crosses weighted by number ofexperiment and location combinations in which the hybrid combinationsoccurs. The mean may be adjusted to remove environmental effects andknown genetic relationships among the varieties.

General combining ability provides an overall score for the inbred overa large number of test crosses. Specific combining ability providesinformation on hybrid combinations formed by PHBBK and a specific inbredparent. A variety such as PHBBK which exhibits good general combiningability may be used in a large number of hybrid combinations.

A general combining ability report for inbred PHBBK is provided in Table4. This data represents the overall mean value for these traits overhundreds of test crosses. Table 4 demonstrates that inbred PHBBK showsgood general combining ability for hybrid production.

Introgression of a New Locus or Trait into PHBBK

PHBBK represents a new base genetic variety into which a new locus ortrait may be introgressed. Direct transformation and backcrossingrepresent two important methods that can be used to accomplish such anintrogression. The term locus conversion is used to designate theproduct of such an introgression.

Locus Conversions of PHBBK

A locus conversion of PHBBK will retain the genetic integrity of PHBBK.The molecular marker data provided in table # as well as theavailability of the seed deposit for determining the genetic profileillustrates the genetic integrity of PHBBK. A locus conversion of PHBBKwill comprise at least 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% of thebase genetics of PHBBK. For example, a locus conversion of PHBBK can bedeveloped when DNA sequences are introduced through backcrossing(Hallauer et al. in Corn and Corn Improvement, Sprague and Dudley, ThirdEd. 1998), with PHBBK utilized as the recurrent parent. Both naturallyoccurring and transgenic DNA sequences may be introduced throughbackcrossing techniques. A backcross conversion may produce a plant witha trait or locus conversion in at least one or more backcrosses,including at least 2 crosses, at least 3 crosses, at least 4 crosses, atleast 5 crosses and the like. Molecular marker assisted breeding orselection may be utilized to reduce the number of backcrosses necessaryto achieve the backcross conversion. For example, see Openshaw, S. J. etal., Marker-assisted Selection in Backcross Breeding, In: ProceedingsSymposium of the Analysis of Molecular Data, August 1994, Crop ScienceSociety of America, Corvallis, Oreg., where it is demonstrated that abackcross conversion can be made in as few as two backcrosses.

The complexity of the backcross conversion method depends on the type oftrait being transferred (single genes or closely linked genes as vs.unlinked genes), the level of expression of the trait, the type ofinheritance (cytoplasmic or nuclear) and the types of parents includedin the cross. It is understood by those of ordinary skill in the artthat for single gene traits that are relatively easy to classify, thebackcross method is effective and relatively easy to manage. (SeeHallauer et al. in Corn and Corn Improvement, Sprague and Dudley, ThirdEd. 1998). Desired traits that may be transferred through backcrossconversion include, but are not limited to, waxy starch, sterility(nuclear and cytoplasmic), fertility restoration, grain color (white),nutritional enhancements, drought resistance, enhanced nitrogenutilization efficiency, altered nitrogen responsiveness, altered fattyacid profile, increased digestibility, low phytate, industrialenhancements, disease resistance (bacterial, fungal or viral), insectresistance, herbicide resistance and yield enhancements. In addition, anintrogression site itself, such as an FRT site, Lox site or other sitespecific integration site, may be inserted by backcrossing and utilizedfor direct insertion of one or more genes of interest into a specificplant variety. In some embodiments of the invention, the number of locithat may be backcrossed into PHBBK is at least 1, 2, 3, 4, or 5 and/orno more than 10, 9, 8, 7, 6, 5, 4, 3, or 2. The seed industry commonlymarkets “triple stacks” of base genetics; which can be varietiescomprising a locus conversion of at least 3 loci. Similarly, “quadruplestacks” would comprise the base genetics and could comprise a locusconversion of at least 4 loci. Stacking of traits is common to those ofordinary skill in the art of plant breeding and stacked traits accountfor a significant percentage of commercial corn hybrid sales. Forexample, figures from Purdue University show that biotech-trait cornaccounted for 61% of all corn acres in 2006 and corn with two or morestacked traits accounted for 11.9 million acres. That's a significantportion of the approximately 80 million acres of corn grown in the U.S.In addition, for 2007 at least one company projects selling moretriple-stack corn hybrids than single trait hybrids. (Wayne Wenzel,“Double, Triple, Quad”, published Nov. 8, 2006, Agweb.com, accessed Dec.4, 2006). A single locus may contain several transgenes, such as atransgene for disease resistance that, in the same expression vector,also contains a transgene for herbicide resistance. The gene forherbicide resistance may be used as a selectable marker and/or as aphenotypic trait. A locus conversion of a site specific integrationsystem allows for the integration of multiple genes at the convertedloci. Further, SSI and FRT technologies known to those of skill in theart in the art may result in multiple gene introgressions at a singlelocus.

The locus conversion may result from either the transfer of a dominantallele or a recessive allele. Selection of progeny containing the traitof interest is accomplished by direct selection for a trait associatedwith a dominant allele. Transgenes transferred via backcrossingtypically function as a dominant single gene trait and are relativelyeasy to classify. Selection of progeny for a trait that is transferredvia a recessive allele, such as the waxy starch characteristic, requiresgrowing and selfing the first backcross generation to determine whichplants carry the recessive alleles. Recessive traits may requireadditional progeny testing in successive backcross generations todetermine the presence of the locus of interest. The last backcrossgeneration is usually selfed to give pure breeding progeny for thegene(s) being transferred, although a backcross conversion with a stablyintrogressed trait may also be maintained by further backcrossing to therecurrent parent with selection for the converted trait.

Along with selection for the trait of interest, progeny are selected forthe phenotype and/or genotype of the recurrent parent. Whileoccasionally additional polynucleotide sequences or genes may betransferred along with the backcross conversion, the backcrossconversion variety “fits into the same hybrid combination as therecurrent parent inbred variety and contributes the effect of theadditional gene added through the backcross.” Poehiman et al. (1995,page 334). It has been proposed that in general there should be at leastfour backcrosses when it is important that the recovered varieties beessentially identical to the recurrent parent except for thecharacteristic being transferred (Fehr 1987, Principles of CultivarDevelopment). However, as noted above, the number of backcrossesnecessary can be reduced with the use of molecular markers. Otherfactors, such as a genetically similar donor parent, may also reduce thenumber of backcrosses necessary.

One process for adding or modifying a trait or locus in maize inbredvariety PHBBK comprises crossing PHBBK plants grown from PHBBK seed withplants of another maize variety that comprise the desired trait orlocus, selecting F1 progeny plants that comprise the desired trait orlocus to produce selected F1 progeny plants, crossing the selectedprogeny plants with the PHBBK plants to produce backcross progenyplants, selecting for backcross progeny plants that have the desiredtrait or locus and the morphological characteristics of maize inbredvariety PHBBK to produce selected backcross progeny plants; andbackcrossing to PHBBK three or more times in succession to produceselected fourth or higher backcross progeny plants that comprise saidtrait or locus. The modified PHBBK may be further characterized ashaving the physiological and morphological characteristics of maizeinbred variety PHBBK listed in Table 1 as determined at the 5%significance level when grown in the same environmental conditionsand/or may be characterized by percent similarity or identity to PHBBKas determined by SSR markers.

Traits are also used by those of ordinary skill in the art tocharacterize progeny. Traits are commonly evaluated at a significancelevel, such as a 1%, 5% or 10% significance level, when measured inplants grown in the same environmental conditions. For example, a locusconversion of PHBBK may be characterized as having the samemorphological and physiological traits as PHBBK. The traits used forcomparison may be those traits shown in Table 1, Table 3, Table 4 orTable 5. Molecular markers can also be used during the breeding processfor the selection of qualitative traits. For example, markers closelylinked to alleles or markers containing sequences within the actualalleles of interest can be used to select plants that contain thealleles of interest during a backcrossing breeding program. The markerscan also be used to select for the genome of the recurrent parent andagainst the genome of the donor parent. Using this procedure canminimize the amount of genome from the donor parent that remains in theselected plants.

The above method may be utilized with fewer backcrosses in appropriatesituations, such as when the donor parent is highly related or markersare used in the selection step. Desired traits that may be used includethose nucleic acids known in the art, some of which are listed herein,that will affect traits through nucleic acid expression or inhibition.Desired loci include the introgression of FRT, Lox and other sites forsite specific integration.

In addition, the above process and other similar processes describedherein may be used to produce F1 hybrid maize seed by adding a step atthe end of the process that comprises crossing PHBBK with theintrogressed trait or locus with a different maize plant and harvestingthe resultant F1 hybrid maize seed.

Male Sterility and Hybrid Seed Production

Hybrid seed production requires elimination or inactivation of pollenproduced by the female inbred parent. Incomplete removal or inactivationof the pollen provides the potential for self-pollination. A reliablemethod of controlling male fertility in plants offers the opportunityfor improved seed production.

PHBBK can be produced in a male-sterile form. There are several ways inwhich a maize plant can be manipulated so that it is male sterile. Theseinclude use of manual or mechanical emasculation (or detasseling), useof one or more genetic factors that confer male sterility, includingcytoplasmic genetic and/or nuclear genetic male sterility, use ofgametocides and the like. A male sterile inbred designated PHBBK mayinclude one or more genetic factors, which result in cytoplasmic geneticand/or nuclear genetic male sterility. All of such embodiments arewithin the scope of the present claims. The male sterility may be eitherpartial or complete male sterility.

Hybrid maize seed is often produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twomaize inbreds are planted in a field, and the pollen-bearing tassels areremoved from one of the inbreds (female). Provided that there issufficient isolation from sources of foreign maize pollen, the ears ofthe detasseled inbred will be fertilized only from the other inbred(male), and the resulting seed is therefore hybrid and will form hybridplants.

The laborious detasseling process can be avoided by using cytoplasmicmale-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile as aresult of genetic factors in the cytoplasm, as opposed to the nucleus,and so nuclear linked genes are not transferred during backcrossing.Thus, this characteristic is inherited exclusively through the femaleparent in maize plants, since only the female provides cytoplasm to thefertilized seed. CMS plants are fertilized with pollen from anotherinbred that is not male-sterile. Pollen from the second inbred may ormay not contribute genes that make the hybrid plants male-fertile, andeither option may be preferred depending on the intended use of thehybrid. The same hybrid seed, a portion produced from detasseled fertilemaize and a portion produced using the CMS system, can be blended toinsure that adequate pollen loads are available for fertilization whenthe hybrid plants are grown. CMS systems have been successfully usedsince the 1950's, and the male sterility trait is routinely backcrossedinto inbred varieties. See Wych, p. 585-586, 1998.

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Inaddition to these methods, Albertsen et al., U.S. Pat. No. 5,432,068,describe a system of nuclear male sterility which includes: identifyinga gene which is critical to male fertility; silencing this native genewhich is critical to male fertility; removing the native promoter fromthe essential male fertility gene and replacing it with an induciblepromoter; inserting this genetically engineered gene back into theplant; and thus creating a plant that is male sterile because theinducible promoter is not “on” resulting in the male fertility gene notbeing transcribed. Fertility is restored by inducing, or turning “on”,the promoter, which in turn allows the gene that confers male fertilityto be transcribed.

These, and the other methods of conferring genetic male sterility in theart, each possess their own benefits and drawbacks. Some other methodsuse a variety of approaches such as delivering into the plant a geneencoding a cytotoxic substance associated with a male tissue specificpromoter or an antisense system in which a gene critical to fertility isidentified and an antisense to that gene is inserted in the plant (seeFabinjanski, et al. EPO 89/3010153.8 publication no. 329,308 and PCTapplication PCT/CA90/00037 published as WO 90/08828).

Another system for controlling male sterility makes use of gametocides.Gametocides are not a genetic system, but rather a topical applicationof chemicals. These chemicals affect cells that are critical to malefertility. The application of these chemicals affects fertility in theplants only for the growing season in which the gametocide is applied(see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application of thegametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach and it is not appropriate in allsituations.

Incomplete control over male fertility may result in self-pollinatedseed being unintentionally harvested and packaged with hybrid seed. Thiswould typically be only female parent seed, because the male plant isgrown in rows that are typically destroyed prior to seed development.Once the seed from the hybrid bag is planted, it is possible to identifyand select these self-pollinated plants. These self-pollinated plantswill be one of the inbred varieties used to produce the hybrid. Thoughthe possibility of inbred PHBBK being included in a hybrid seed bagexists, the occurrence is very low because much care is taken by seedcompanies to avoid such inclusions. It is worth noting that hybrid seedis sold to growers for the production of grain or forage and not forbreeding or seed production. These self-pollinated plants can beidentified and selected by one skilled in the art due to their lessvigorous appearance for vegetative and/or reproductive characteristics,including shorter plant height, small ear size, ear and kernel shape,cob color, or other characteristics.

Identification of these self-pollinated varieties can also beaccomplished through molecular marker analyses. See, “The Identificationof Female Selfs in Hybrid Maize: A Comparison Using Electrophoresis andMorphology”, Smith, J. S. C. and Wych, R. D., Seed Science andTechnology 14, 1-8 (1995), the disclosure of which is expresslyincorporated herein by reference. Through these technologies, thehomozygosity of the self pollinated variety can be verified by analyzingallelic composition at various loci along the genome. Those methodsallow for rapid identification of the invention disclosed herein. Seealso, “Identification of Atypical Plants in Hybrid Maize Seed byPostcontrol and Electrophoresis” Sarca, V. et al., Probleme de GeneticaTeoritica si Aplicata Vol. 20 (1) p. 29-42.

An embodiment of this invention is a process for producing seed of PHBBKcomprising planting a collection of seed comprising seed of a hybrid,one of whose parents is inbred PHBBK said collection also comprisingseed of said inbred, growing plants from said collection of seed,identifying inbred parent plants, selecting said inbred parent plant;and controlling pollination to preserve the homozygosity of said inbredparent plant.

Transformation

The advent of new molecular biological techniques has allowed theisolation and characterization of genetic elements with specificfunctions, such as encoding specific protein products. Scientists in thefield of plant biology developed a strong interest in engineering thegenome of plants to contain and express foreign genetic elements, oradditional, or modified versions of native or endogenous geneticelements in order to alter the traits of a plant in a specific manner.Any DNA sequences, whether from a different species or from the samespecies, which are inserted into the genome using transformation arereferred to herein collectively as “transgenes”. In some embodiments ofthe invention, a transformed variant of PHBBK may comprise at least onetransgene but could contain at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10and/or no more than 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2.Over the last fifteen to twenty years several methods for producingtransgenic plants have been developed, and the present invention alsorelates to transformed versions of the claimed inbred maize varietyPHBBK as well as hybrid combinations thereof.

Numerous methods for plant transformation have been developed, includingbiological and physical plant transformation protocols. See, forexample, Miki et al., “Procedures for Introducing Foreign DNA intoPlants” in Methods in Plant Molecular Biology and Biotechnology, Glick,B.R. and Thompson, J.E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages67-88 and Armstrong, “The First Decade of Maize Transformation: A Reviewand Future Perspective” (Maydica 44:101-109, 1999). In addition,expression vectors and in vitro culture methods for plant cell or tissuetransformation and regeneration of plants are available. See, forexample, Gruber et al., “Vectors for Plant Transformation” in Methods inPlant Molecular Biology and Biotechnology, Glick, B.R. and Thompson,J.E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages 89-119.

The most prevalent types of plant transformation involve theconstruction of an expression vector. Such a vector comprises a DNAsequence that contains a gene under the control of or operatively linkedto a regulatory element, for example a promoter. The vector may containone or more genes and one or more regulatory elements.

A genetic trait which has been engineered into the genome of aparticular maize plant using transformation techniques, could be movedinto the genome of another variety using traditional breeding techniquesthat are well known in the plant breeding arts. For example, abackcrossing approach is commonly used to move a transgene from atransformed maize plant to an elite inbred variety, and the resultingprogeny would then comprise the transgene(s). Also, if an inbred varietywas used for the transformation then the transgenic plants could becrossed to a different inbred in order to produce a transgenic hybridmaize plant.

Various genetic elements can be introduced into the plant genome usingtransformation. These elements include, but are not limited to genes;coding sequences; inducible, constitutive, and tissue specificpromoters; enhancing sequences; and signal and targeting sequences. Forexample, see the traits, genes and transformation methods listed in U.S.Pat. Nos. 6,118,055 and 6,284,953, which are herein incorporated byreference. In addition, transformability of a variety can be increasedby introgressing the trait of high transformability from another varietyknown to have high transformability, such as Hi-II. See U.S. PatentApplication Publication US2004/0016030 (2004).

With transgenic plants according to the present invention, a foreignprotein can be produced in commercial quantities. Thus, techniques forthe selection and propagation of transformed plants, which are wellunderstood in the art, yield a plurality of transgenic plants that areharvested in a conventional manner, and a foreign protein then can beextracted from a tissue of interest or from total biomass. Proteinextraction from plant biomass can be accomplished by known methods whichare discussed, for example, by Heney and Orr, Anal. Biochem. 114: 92-6(1981).

Transgenes can be mapped by one of ordinary skill in the art and suchtechniques are well known to those of ordinary skill in the art. Forexemplary methodologies in this regard, see for example, Glick andThompson, Methods in Plant Molecular Biology and Biotechnology 269-284(CRC Press, Boca Raton, 1993).

Likewise, by means of the present invention, plants can be geneticallyengineered to express various phenotypes of agronomic interest. Throughthe transformation of maize the expression of genes can be altered toenhance disease resistance, insect resistance, herbicide resistance,agronomic traits, grain quality and other traits. Transformation canalso be used to insert DNA sequences which control or help controlmale-sterility. DNA sequences native to maize as well as non-native DNAsequences can be transformed into maize and used to alter levels ofnative or non-native proteins. Various promoters, targeting sequences,enhancing sequences, and other DNA sequences can be inserted into themaize genome for the purpose of altering the expression of proteins.Reduction of the activity of specific genes (also known as genesilencing, or gene suppression) is desirable for several aspects ofgenetic engineering in plants.

Many techniques for gene silencing are well known to one of skill in theart, including but not limited to knock-outs (such as by insertion of atransposable element such as mu (Vicki Chandler, The Maize Handbook ch.118 (Springer-Verlag 1994) or other genetic elements such as a FRT, Loxor other site specific integration site, antisense technology (see,e.g., Sheehy et al. (1988) PNAS USA 85:8805-8809; and U.S. Pat. Nos.5,107,065; 5,453,566; and 5,759,829); co-suppression (e.g., Taylor(1997) Plant Cell 9:1245; Jorgensen (1990) Trends Biotech.8(12):340-344; Flavell (1994) PNAS USA 91:3490-3496; Finnegan et al.(1994) Bio/Technology 12: 883-888; and Neuhuber et al. (1994) Mol. Gen.Genet. 244:230-241); RNA interference (Napoli et al. (1990) Plant Cell2:279-289; U.S. Pat. No. 5,034,323; Sharp (1999) Genes Dev. 13:139-141;Zamore et al. (2000) Cell 101:25-33; and Montgomery et al. (1998) PNASUSA 95:15502-15507), virus-induced gene silencing (Burton, et al. (2000)Plant Cell 12:691-705; and Baulcombe (1999) Curr. Op. Plant Bio.2:109-113); target-RNA-specific ribozymes (Haseloff et al. (1988) Nature334: 585-591); hairpin structures (Smith et al. (2000) Nature407:319-320; WO 99/53050; and WO 98/53083); MicroRNA (Aukerman & Sakai(2003) Plant Cell 15:2730-2741); ribozymes (Steinecke et al. (1992) EMBOJ. 11:1525; and Perriman et al. (1993) Antisense Res. Dev. 3:253);oligonucleotide mediated targeted modification (e.g., WO 03/076574 andWO 99/25853); Zn-finger targeted molecules (e.g., WO 01/52620; WO03/048345; and WO 00/42219); and other methods or combinations of theabove methods known to those of skill in the art.

Exemplary nucleotide sequences that may be altered by geneticengineering include, but are not limited to, those categorized below.

1. Transgenes that Confer Resistance to Insects or Disease and thatEncode:

(A) Plant disease resistance genes. Plant defenses are often activatedby specific interaction between the product of a disease resistance gene(R) in the plant and the product of a corresponding avirulence (Avr)gene in the pathogen. A plant variety can be transformed with clonedresistance gene to engineer plants that are resistant to specificpathogen strains. See, for example Jones et al., Science 266: 789 (1994)(cloning of the tomato Cf-9 gene for resistance to Cladosporium fulvum);Martin et al., Science 262: 1432 (1993) (tomato Pto gene for resistanceto Pseudomonas syringae pv. tomato encodes a protein kinase); Mindrinoset al., Cell 78: 1089 (1994) (Arabidopsis RSP2 gene for resistance toPseudomonas syringae); McDowell & Woffenden, (2003) Trends Biotechnol.21(4): 178-83 and Toyoda et al., (2002) Transgenic Res. 11 (6):567-82. Aplant resistant to a disease is one that is more resistant to a pathogenas compared to the wild type plant.

(B) A Bacillus thuringiensis protein, a derivative thereof or asynthetic polypeptide modeled thereon. See, for example, Geiser et al.,Gene 48: 109 (1986), who disclose the cloning and nucleotide sequence ofa Bt delta-endotoxin gene. Moreover, DNA molecules encodingdelta-endotoxin genes can be purchased from American Type CultureCollection (Rockville, Md.), for example, under ATCC Accession Nos.40098, 67136, 31995 and 31998. Other examples of Bacillus thuringiensistransgenes being genetically engineered are given in the followingpatents and patent applications and hereby are incorporated by referencefor this purpose: U.S. Pat. Nos. 5,188,960; 5,689,052; 5,880,275; WO91/14778; WO 99/31248; WO 01/12731; WO 99/24581; WO 97/40162 and U.S.application Ser. Nos. 10/032,717; 10/414,637; and 10/606,320.

(C) An insect-specific hormone or pheromone such as an ecdysteroid andjuvenile hormone, a variant thereof, a mimetic based thereon, or anantagonist or agonist thereof. See, for example, the disclosure byHammock et al., Nature 344: 458 (1990), of baculovirus expression ofcloned juvenile hormone esterase, an inactivator of juvenile hormone.

(D) An insect-specific peptide which, upon expression, disrupts thephysiology of the affected pest. For example, see the disclosures ofRegan, J. Biol. Chem. 269: 9 (1994) (expression cloning yields DNAcoding for insect diuretic hormone receptor); Pratt et al., Biochem.Biophys. Res. Comm. 163: 1243 (1989) (an allostatin is identified inDiploptera puntata); Chattopadhyay et al. (2004) Critical Reviews inMicrobiology 30 (1): 33-54 2004; Zjawiony (2004) J Nat Prod 67 (2):300-310; Carlini & Grossi-de-Sa (2002) Toxicon, 40 (11): 1515-1539;Ussuf et al. (2001) Curr Sci. 80 (7): 847-853; and Vasconcelos &Oliveira (2004) Toxicon 44 (4): 385-403. See also U.S. Pat. No.5,266,317 to Tomalski et al., who disclose genes encodinginsect-specific toxins.

(E) An enzyme responsible for a hyperaccumulation of a monterpene, asesquiterpene, a steroid, hydroxamic acid, a phenylpropanoid derivativeor another non-protein molecule with insecticidal activity.

(F) An enzyme involved in the modification, including thepost-translational modification, of a biologically active molecule; forexample, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme,a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, aphosphatase, a kinase, a phosphorylase, a polymerase, an elastase, achitinase and a glucanase, whether natural or synthetic. See PCTapplication WO 93/02197 in the name of Scott et al., which discloses thenucleotide sequence of a callase gene. DNA molecules which containchitinase-encoding sequences can be obtained, for example, from the ATCCunder Accession Nos. 39637 and 67152. See also Kramer et al., InsectBiochem. Molec. Biol. 23: 691 (1993), who teach the nucleotide sequenceof a cDNA encoding tobacco hookworm chitinase, and Kawalleck et al.,Plant Molec. Biol. 21: 673 (1993), who provide the nucleotide sequenceof the parsley ubi4-2 polyubiquitin gene, U.S. application Ser. Nos.10/389,432,10/692,367, and U.S. Pat. No. 6,563,020.

(G) A molecule that stimulates signal transduction. For example, see thedisclosure by Botella et al., Plant Molec. Biol. 24: 757 (1994), ofnucleotide sequences for mung bean calmodulin cDNA clones, and Griess etal., Plant Physiol. 104: 1467 (1994), who provide the nucleotidesequence of a maize calmodulin cDNA clone.

(H) A hydrophobic moment peptide. See PCT application WO 95/16776 andU.S. Pat. No. 5,580,852 (disclosure of peptide derivatives ofTachyplesin which inhibit fungal plant pathogens) and PCT application WO95/18855 and U.S. Pat. No. 5,607,914) (teaches synthetic antimicrobialpeptides that confer disease resistance).

(I) A membrane permease, a channel former or a channel blocker. Forexample, see the disclosure by Jaynes et al., Plant Sci. 89: 43 (1993),of heterologous expression of a cecropin-beta lytic peptide analog torender transgenic tobacco plants resistant to Pseudomonas solanacearum.

(J) A viral-invasive protein or a complex toxin derived therefrom. Forexample, the accumulation of viral coat proteins in transformed plantcells imparts resistance to viral infection and/or disease developmenteffected by the virus from which the coat protein gene is derived, aswell as by related viruses. See Beachy et al., Ann. Rev. Phytopathol.28: 451 (1990). Coat protein-mediated resistance has been conferred upontransformed plants against alfalfa mosaic virus, cucumber mosaic virus,tobacco streak virus, potato virus X, potato virus Y, tobacco etchvirus, tobacco rattle virus and tobacco mosaic virus. Id.

(K) An insect-specific antibody or an immunotoxin derived therefrom.Thus, an antibody targeted to a critical metabolic function in theinsect gut would inactivate an affected enzyme, killing the insect. Cf.Taylor et al., Abstract #497, SEVENTH INT'L SYMPOSIUM ON MOLECULARPLANT-MICROBE INTERACTIONS (Edinburgh, Scotland, 1994) (enzymaticinactivation in transgenic tobacco via production of single-chainantibody fragments).

(L) A virus-specific antibody. See, for example, Tavladoraki et al.,Nature 366: 469 (1993), who show that transgenic plants expressingrecombinant antibody genes are protected from virus attack.

(M) A developmental-arrestive protein produced in nature by a pathogenor a parasite. Thus, fungal endo alpha-1,4-D-polygalacturonasesfacilitate fungal colonization and plant nutrient release bysolubilizing plant cell wall homo-alpha-1,4-D-galacturonase. See Lamb etal., Bio/Technology 10: 1436 (1992). The cloning and characterization ofa gene which encodes a bean endopolygalacturonase-inhibiting protein isdescribed by Toubart et al., Plant J. 2: 367 (1992).

(N) A developmental-arrestive protein produced in nature by a plant. Forexample, Logemann et al., Bio/Technology 10: 305 (1992), have shown thattransgenic plants expressing the barley ribosome-inactivating gene havean increased resistance to fungal disease.

(O) Genes involved in the Systemic Acquired Resistance (SAR) Responseand/or the pathogenesis related genes. Briggs, S., Current Biology,5(2):128-131 (1995), Pieterse & Van Loon (2004) Curr. Opin. Plant Bio.7(4):456-64 and Somssich (2003) Cell 113(7):815-6.

(P) Antifungal genes (Cornelissen and Melchers, Pl. Physiol.101:709-712, (1993) and Parijs et al., Planta 183:258-264, (1991) andBushnell et al., Can. J. of Plant Path. 20(2):137-149 (1998). Also seeU.S. Pat. No. 6,875,907.

(Q) Detoxification genes, such as for fumonisin, beauvericin,moniliformin and zearalenone and their structurally related derivatives.For example, see U.S. Pat. No. 5,792,931.

(R) Cystatin and cysteine proteinase inhibitors. See U.S. applicationSer. No. 10/947,979.

(S) Defensin genes. See WO03000863 and U.S. application Ser. No.10/178,213.

(T) Genes conferring resistance to nematodes. See WO 03/033651 and Urwinet. al., Planta 204:472-479 (1998), Williamson (1999) Curr Opin PlantBio. 2(4):327-31.

(U) Genes such as rcg1 conferring resistance to Anthracnose stalk rot,which is caused by the fungus Colletotrichum graminiola. See M. Jung etal., Generation-means analysis and quantitative trait locus mapping ofAnthracnose Stalk Rot genes in Maize, Theor. Appl. Genet. (1994)89:413-418 which is incorporated by reference for this purpose, as wellas U.S. Patent Application 60/675,664, which is also incorporated byreference for this purpose.

2. Transgenes that Confer Resistance to a Herbicide, for Example:

(A) A herbicide that inhibits the growing point or meristem, such as animidazolinone or a sulfonylurea. Exemplary genes in this category codefor mutant ALS and AHAS enzyme as described, for example, by Lee et al.,EMBO J. 7: 1241 (1988), and Miki et al., Theor. Appl. Genet. 80: 449(1990), respectively. See also, U.S. Pat. Nos. 5,605,011; 5,013,659;5,141,870; 5,767,361; 5,731,180; 5,304,732; 4,761,373; 5,331,107;5,928,937; and 5,378,824; and international publication WO 96/33270,which are incorporated herein by reference for this purpose.

(B) Glyphosate (resistance imparted by mutant5-enolpyruvl-3-phosphikimate synthase (EPSP) and aroA genes,respectively) and other phosphono compounds such as glufosinate(phosphinothricin acetyl transferase (PAT) and Streptomyceshygroscopicus phosphinothricin acetyl transferase (bar) genes), andpyridinoxy or phenoxy proprionic acids and cycloshexones (ACCaseinhibitor-encoding genes). See, for example, U.S. Pat. No. 4,940,835 toShah et al., which discloses the nucleotide sequence of a form of EPSPSwhich can confer glyphosate resistance. U.S. Pat. No. 5,627,061 to Barryet al. also describes genes encoding EPSPS enzymes. See also U.S. Pat.Nos. 6,566,587; 6,338,961; 6,248,876 B1; 6,040,497; 5,804,425;5,633,435; 5,145,783; 4,971,908; 5,312,910; 5,188,642; 4,940,835;5,866,775; 6,225,114 B1; 6,130,366; 5,310,667; 4,535,060; 4,769,061;5,633,448; 5,510,471; Re. 36,449; RE 37,287 E; and 5,491,288; andinternational publications EP1173580; WO 01/66704; EP1173581 andEP1173582, which are incorporated herein by reference for this purpose.Glyphosate resistance is also imparted to plants that express a genethat encodes a glyphosate oxido-reductase enzyme as described more fullyin U.S. Pat. Nos. 5,776,760 and 5,463,175, which are incorporated hereinby reference for this purpose. In addition glyphosate resistance can beimparted to plants by the over expression of genes encoding glyphosateN-acetyltransferase. See, for example, U.S. application Ser. Nos.01/46227; 10/427,692 and 10/427,692. A DNA molecule encoding a mutantaroA gene can be obtained under ATCC accession No. 39256, and thenucleotide sequence of the mutant gene is disclosed in U.S. Pat. No.4,769,061 to Comai. European Patent Application No. 0 333 033 to Kumadaet al. and U.S. Pat. No. 4,975,374 to Goodman et al. disclose nucleotidesequences of glutamine synthetase genes which confer resistance toherbicides such as L-phosphinothricin. The nucleotide sequence of aphosphinothricin-acetyl-transferase gene is provided in European PatentNo. 0 242 246 and 0 242 236 to Leemans et al. De Greef et al.,Bio/Technology 7: 61 (1989), describe the production of transgenicplants that express chimeric bar genes coding for phosphinothricinacetyl transferase activity. See also, U.S. Pat. Nos. 5,969,213;5,489,520; 5,550,318; 5,874,265; 5,919,675; 5,561,236; 5,648,477;5,646,024; 6,177,616 B1; and 5,879,903, which are incorporated herein byreference for this purpose. Exemplary genes conferring resistance tophenoxy proprionic acids and cycloshexones, such as sethoxydim andhaloxyfop, are the Acc1-S1, Acc1-S2 and Acc1-S3 genes described byMarshall et al., Theor. Appl. Genet. 83: 435 (1992).

(C) A herbicide that inhibits photosynthesis, such as a triazine (psbAand gs+ genes) and a benzonitrile (nitrilase gene). Przibilla et al.,Plant Cell 3: 169 (1991), describe the transformation of Chlamydomonaswith plasmids encoding mutant psbA genes. Nucleotide sequences fornitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, andDNA molecules containing these genes are available under ATCC AccessionNos. 53435, 67441 and 67442. Cloning and expression of DNA coding for aglutathione S-transferase is described by Hayes et al., Biochem. J.285:173 (1992).

(D) Acetohydroxy acid synthase, which has been found to make plants thatexpress this enzyme resistant to multiple types of herbicides, has beenintroduced into a variety of plants (see, e.g., Hattori et al. (1995)Mol Gen Genet 246:419). Other genes that confer resistance to herbicidesinclude: a gene encoding a chimeric protein of rat cytochrome P4507A1and yeast NADPH-cytochrome P450 oxidoreductase (Shiota et al. (1994)Plant Physiol. 106(1):17-23), genes for glutathione reductase andsuperoxide dismutase (Aono et al. (1995) Plant Cell Physiol 36:1687, andgenes for various phosphotransferases (Datta et al. (1992) Plant MolBiol 20:619).

(E) Protoporphyrinogen oxidase (protox) is necessary for the productionof chlorophyll, which is necessary for all plant survival. The protoxenzyme serves as the target for a variety of herbicidal compounds. Theseherbicides also inhibit growth of all the different species of plantspresent, causing their total destruction. The development of plantscontaining altered protox activity which are resistant to theseherbicides are described in U.S. Pat. Nos. 6,288,306 B1; 6,282,837 B1;and 5,767,373; and international publication WO 01/12825.

3. Transgenes that confer or contribute to an altered graincharacteristic, Such As:

(A) Altered fatty acids, for example, by

-   -   (1) Down-regulation of stearoyl-ACP desaturase to increase        stearic acid content of the plant. See Knultzon et al., Proc.        Natl. Acad. Sci. USA 89: 2624 (1992) and WO99/64579 (Genes for        Desaturases to Alter Lipid Profiles in Corn),    -   (2) Elevating oleic acid via FAD-2 gene modification and/or        decreasing linolenic acid via FAD-3 gene modification (see U.S.        Pat. Nos. 6,063,947; 6,323,392; 6,372,965 and WO 93/11245),    -   (3) Altering conjugated linolenic or linoleic acid content, such        as in WO 01/12800,    -   (4) Altering LEC1, AGP, Dek1, Superal1, mi1ps, various Ipa genes        such as Ipa1, Ipa3, hpt or hggt. For example, see WO 02/42424,        WO 98/22604, WO 03/011015, U.S. Pat. No. 6,423,886, U.S. Pat.        No. 6,197,561, U.S. Pat. No. 6,825,397, US2003/0079247,        US2003/0204870, WO02/057439, WO03/011015 and Rivera-Madrid, R.        et. al. Proc. Natl. Acad. Sci. 92:5620-5624 (1995).

(B) Altered phosphorus content, for example, by the

-   -   (1) Introduction of a phytase-encoding gene would enhance        breakdown of phytate, adding more free phosphate to the        transformed plant. For example, see Van Hartingsveldt et al.,        Gene 127: 87 (1993), for a disclosure of the nucleotide sequence        of an Aspergillus niger phytase gene.    -   (2) Up-regulation of a gene that reduces phytate content. In        maize, this, for example, could be accomplished, by cloning and        then re-introducing DNA associated with one or more of the        alleles, such as the LPA alleles, identified in maize mutants        characterized by low levels of phytic acid, such as in Raboy et        al., Maydica 35: 383 (1990) and/or by altering inositol kinase        activity as in WO 02/059324, US2003/0009011, WO 03/027243,        US2003/0079247, WO 99/05298, U.S. Pat. No. 6,197,561, U.S. Pat.        No. 6,291,224, U.S. Pat. No. 6,391,348, WO2002/059324,        US2003/0079247, Wo98/45448, WO99/55882, WO01/04147.

(C) Altered carbohydrates effected, for example, by altering a gene foran enzyme that affects the branching pattern of starch or a genealtering thioredoxin such as NTR and/or TRX (see U.S. Pat. No. 6,531,648which is incorporated by reference for this purpose) and/or a gamma zeinknock out or mutant such as cs27 or TUSC27 or en27 (See U.S. Pat. No.6,858,778 and US2005/0160488, US2005/0204418; which are incorporated byreference for this purpose). See Shiroza et al., J. Bacteriol. 170: 810(1988) (nucleotide sequence of Streptococcus mutans fructosyltransferasegene), Steinmetz et al., Mol. Gen. Genet. 200: 220 (1985) (nucleotidesequence of Bacillus subtilis levansucrase gene), Pen et al.,Bio/Technology 10: 292 (1992) (production of transgenic plants thatexpress Bacillus licheniformis alpha-amylase), Elliot et al., PlantMolec. Biol. 21: 515 (1993) (nucleotide sequences of tomato invertasegenes), Søgaard et al., J. Biol. Chem. 268: 22480 (1993) (site-directedmutagenesis of barley alpha-amylase gene), and Fisher et al., PlantPhysiol. 102: 1045 (1993) (maize endosperm starch branching enzyme II),WO 99/10498 (improved digestibility and/or starch extraction throughmodification of UDP-D-xylose 4-epimerase, Fragile 1 and 2, Ref1, HCHL,C4H), U.S. Pat. No. 6,232,529 (method of producing high oil seed bymodification of starch levels (AGP)). The fatty acid modification genesmentioned above may also be used to affect starch content and/orcomposition through the interrelationship of the starch and oilpathways.

(D) Altered antioxidant content or composition, such as alteration oftocopherol or tocotrienols. For example, see U.S. Pat. No. 6,787,683,US2004/0034886 and WO 00/68393 involving the manipulation of antioxidantlevels through alteration of a phytl prenyl transferase (ppt), WO03/082899 through alteration of a homogentisate geranyl geranyltransferase (hggt).

(E) Altered essential seed amino acids. For example, see U.S. Pat. No.6,127,600 (method of increasing accumulation of essential amino acids inseeds), U.S. Pat. No. 6,080,913 (binary methods of increasingaccumulation of essential amino acids in seeds), U.S. Pat. No. 5,990,389(high lysine), WO99/40209 (alteration of amino acid compositions inseeds), WO99/29882 (methods for altering amino acid content ofproteins), U.S. Pat. No. 5,850,016 (alteration of amino acidcompositions in seeds), WO98/20133 (proteins with enhanced levels ofessential amino acids), U.S. Pat. No. 5,885,802 (high methionine), U.S.Pat. No. 5,885,801 (high threonine), U.S. Pat. No. 6,664,445 (plantamino acid biosynthetic enzymes), U.S. Pat. No. 6,459,019 (increasedlysine and threonine), U.S. Pat. No. 6,441,274 (plant tryptophansynthase beta subunit), U.S. Pat. No. 6,346,403 (methionine metabolicenzymes), U.S. Pat. No. 5,939,599 (high sulfur), U.S. Pat. No. 5,912,414(increased methionine), WO98/56935 (plant amino acid biosyntheticenzymes), WO98/45458 (engineered seed protein having higher percentageof essential amino acids), WO98/42831 (increased lysine), U.S. Pat. No.5,633,436 (increasing sulfur amino acid content), U.S. Pat. No.5,559,223 (synthetic storage proteins with defined structure containingprogrammable levels of essential amino acids for improvement of thenutritional value of plants), WO96/01905 (increased threonine),WO95/15392 (increased lysine), US2003/0163838, US2003/0150014,US2004/0068767, U.S. Pat. No. 6,803,498, WO01/79516, and WO0/09706 (CesA: cellulose synthase), U.S. Pat. No. 6,194,638 (hemicellulose), U.S.Pat. No. 6,399,859 and US2004/0025203 (UDPGdH), U.S. Pat. No. 6,194,638(RGP).

4. Genes that Control Male-Sterility

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Inaddition to these methods, Albertsen et al., U.S. Pat. No. 5,432,068,describe a system of nuclear male sterility which includes: identifyinga gene which is critical to male fertility; silencing this native genewhich is critical to male fertility; removing the native promoter fromthe essential male fertility gene and replacing it with an induciblepromoter; inserting this genetically engineered gene back into theplant; and thus creating a plant that is male sterile because theinducible promoter is not “on” resulting in the male fertility gene notbeing transcribed. Fertility is restored by inducing, or turning “on”,the promoter, which in turn allows the gene that confers male fertilityto be transcribed.

(A) Introduction of a deacetylase gene under the control of atapetum-specific promoter and with the application of the chemicalN-Ac-PPT (WO 01/29237).

(B) Introduction of various stamen-specific promoters (WO 92/13956, WO92/13957).

(C) Introduction of the barnase and the barstar gene (Paul et al. PlantMol. Biol. 19:611-622, 1992).

For additional examples of nuclear male and female sterility systems andgenes, see also, U.S. Pat. Nos. 5,859,341; 6,297,426; 5,478,369;5,824,524; 5,850,014; and 6,265,640; all of which are herebyincorporated by reference.

5. Genes that create a site for site specific DNA integration. Thisincludes the introduction of FRT sites that may be used in the FLP/FRTsystem and/or Lox sites that may be used in the Cre/Loxp system. Forexample, see Lyznik, et al., Site-Specific Recombination for GeneticEngineering in Plants, Plant Cell Rep (2003) 21:925-932 and WO 99/25821,which are hereby incorporated by reference. Other systems that may beused include the Gin recombinase of phage Mu (Maeser et al., 1991; VickiChandler, The Maize Handbook ch. 118 (Springer-Verlag 1994), the Pinrecombinase of E. coli (Enomoto et al., 1983), and the R/RS system ofthe pSR1 plasmid (Araki et al., 1992).6. Genes that affect abiotic stress resistance (including but notlimited to flowering, ear and seed development, enhancement of nitrogenutilization efficiency, altered nitrogen responsiveness, droughtresistance or tolerance, cold resistance or tolerance, and saltresistance or tolerance) and increased yield under stress. For example,see: WO 00/73475 where water use efficiency is altered throughalteration of malate; U.S. Pat. No. 5,892,009, U.S. Pat. No. 5,965,705,U.S. Pat. No. 5,929,305, U.S. Pat. No. 5,891,859, U.S. Pat. No.6,417,428, U.S. Pat. No. 6,664,446, U.S. Pat. No. 6,706,866, U.S. Pat.No. 6,717,034, U.S. Pat. No. 6,801,104, WO2000060089, WO2001026459,WO2001035725, WO2001034726, WO2001035727, WO2001036444, WO2001036597,WO2001036598, WO2002015675, WO2002017430, WO2002077185, WO2002079403,WO2003013227, WO2003013228, WO2003014327, WO2004031349, WO2004076638,WO9809521, and WO9938977 describing genes, including CBF genes andtranscription factors effective in mitigating the negative effects offreezing, high salinity, and drought on plants, as well as conferringother positive effects on plant phenotype; US2004/0148654 and WO01/36596where abscisic acid is altered in plants resulting in improved plantphenotype such as increased yield and/or increased tolerance to abioticstress; WO2000/006341, WO04/090143, U.S. application Ser. Nos.10/817,483 and 09/545,334 where cytokinin expression is modifiedresulting in plants with increased stress tolerance, such as droughttolerance, and/or increased yield. Also see WO0202776, WO2003052063,JP2002281975, U.S. Pat. No. 6,084,153, WO0164898, U.S. Pat. No.6,177,275, and U.S. Pat. No. 6,107,547 (enhancement of nitrogenutilization and altered nitrogen responsiveness). For ethylenealteration, see US20040128719, US20030166197 and WO200032761. For planttranscription factors or transcriptional regulators of abiotic stress,see e.g. US20040098764 or US20040078852.

Other genes and transcription factors that affect plant growth andagronomic traits such as yield, flowering, plant growth and/or plantstructure, can be introduced or introgressed into plants, see e.g.WO97/49811 (LHY), WO98/56918 (ESD4), WO97/10339 and U.S. Pat. No.6,573,430 (TFL), U.S. Pat. No. 6,713,663 (FT), WO96/14414 (CON),WO96/38560, WO01/21822 (VRN1), WO00/44918 (VRN2), WO99/49064 (GI),WO00/46358 (FRI), WO97/29123, U.S. Pat. No. 6,794,560, U.S. Pat. No.6,307,126 (GAI), WO99/09174 (D8 and Rht), and WO2004076638 andWO2004031349 (transcription factors).

Using PHBBK to Develop Another Maize Plant

Inbred maize varieties such as PHBBK are typically developed for use inthe production of hybrid maize varieties. However, inbred varieties suchas PHBBK also provide a source of breeding material that may be used todevelop new maize inbred varieties. Plant breeding techniques known inthe art and used in a maize plant breeding program include, but are notlimited to, recurrent selection, mass selection, bulk selection, massselection, backcrossing, pedigree breeding, open pollination breeding,restriction fragment length polymorphism enhanced selection, geneticmarker enhanced selection, making double haploids, and transformation.Often combinations of these techniques are used. The development ofmaize hybrids in a maize plant breeding program requires, in general,the development of homozygous inbred varieties, the crossing of thesevarieties, and the evaluation of the crosses. There are many analyticalmethods available to evaluate the result of a cross. The oldest and mosttraditional method of analysis is the observation of phenotypic traitsbut genotypic analysis may also be used.

This invention is also directed to methods for producing a maize plantby crossing a first parent maize plant with a second parent maize plantwherein either the first or second parent maize plant is an inbred maizeplant of the variety PHBBK. The other parent may be any other maizeplant, such as another inbred variety or a plant that is part of asynthetic or natural population. Any such methods using the inbred maizevariety PHBBK are part of this invention: selfing, sibbing, backcrosses,mass selection, pedigree breeding, bulk selection, hybrid production,crosses to populations, and the like. These methods are well known inthe art and some of the more commonly used breeding methods aredescribed below. Descriptions of breeding methods can also be found inone of several reference books (e.g., Allard, Principles of PlantBreeding, 1960; Simmonds, Principles of Crop Improvement, 1979; Fehr,“Breeding Methods for Cultivar Development”, Production and Uses, 2^(nd)ed., Wilcox editor, 1987 the disclosure of which is incorporated hereinby reference).

Pedigree Breeding

Pedigree breeding starts with the crossing of two genotypes, such asPHBBK and one other elite inbred variety having one or more desirablecharacteristics that is lacking or which complements PHBBK. If the twooriginal parents do not provide all the desired characteristics, othersources can be included in the breeding population. In the pedigreemethod, superior plants are selfed and selected in successive filialgenerations. In the succeeding filial generations the heterozygouscondition gives way to homogeneous varieties as a result ofself-pollination and selection. Typically in the pedigree method ofbreeding, five or more successive filial generations of selfing andselection is practiced: F1→F2; F2→F3; F3→F4; F4→F5, etc. After asufficient amount of inbreeding, successive filial generations willserve to increase seed of the developed inbred. Preferably, the inbredvariety comprises homozygous alleles at about 95% or more of its loci.

In addition to being used to create a backcross conversion, backcrossingcan also be used in combination with pedigree breeding to modify PHBBKand a hybrid that is made using the modified PHBBK. As discussedpreviously, backcrossing can be used to transfer one or morespecifically desirable traits from one variety, the donor parent, to aninbred called the recurrent parent, which has overall good agronomiccharacteristics yet lacks that desirable trait or traits. However, thesame procedure can be used to move the progeny toward the genotype ofthe recurrent parent but at the same time retain many components of thenon-recurrent parent by stopping the backcrossing at an early stage andproceeding with selfing and selection. For example, an F1, such as acommercial hybrid, is created. This commercial hybrid may be backcrossedto one of its parent varieties to create a BC1 or BC2. Progeny areselfed and selected so that the newly developed inbred has many of theattributes of the recurrent parent and yet several of the desiredattributes of the non-recurrent parent. This approach leverages thevalue and strengths of the recurrent parent for use in new hybrids andbreeding.

Therefore, an embodiment of this invention is a method of obtaining amolecular marker profile of maize inbred variety PHBBK and using themolecular marker profile to select for a progeny plant with the desiredtrait and the molecular marker profile of PHBBK.

Recurrent Selection and Mass Selection

Recurrent selection is a method used in a plant breeding program toimprove a population of plants. PHBBK is suitable for use in a recurrentselection program. The method entails individual plants crosspollinating with each other to form progeny. The progeny are grown andthe superior progeny selected by any number of selection methods, whichinclude individual plant, half-sib progeny, full-sib progeny, selfedprogeny and topcrossing. The selected progeny are cross pollinated witheach other to form progeny for another population. This population isplanted and again superior plants are selected to cross pollinate witheach other. Recurrent selection is a cyclical process and therefore canbe repeated as many times as desired. The objective of recurrentselection is to improve the traits of a population. The improvedpopulation can then be used as a source of breeding material to obtaininbred varieties to be used in hybrids or used as parents for asynthetic cultivar. A synthetic cultivar is the resultant progeny formedby the intercrossing of several selected inbreds.

PHBBK is suitable for use in mass selection. Mass selection is a usefultechnique when used in conjunction with molecular marker enhancedselection. In mass selection seeds from individuals are selected basedon phenotype and/or genotype. These selected seeds are then bulked andused to grow the next generation. Bulk selection requires growing apopulation of plants in a bulk plot, allowing the plants toself-pollinate, harvesting the seed in bulk and then using a sample ofthe seed harvested in bulk to plant the next generation. Instead of selfpollination, directed pollination could be used as part of the breedingprogram.

Mutation Breeding

Mutation breeding is one of many methods that could be used to introducenew traits into PHBBK. PHBBK is suitable for use in a mutation breedingprogram. Mutations that occur spontaneously or are artificially inducedcan be useful sources of variability for a plant breeder. The goal ofartificial mutagenesis is to increase the rate of mutation for a desiredcharacteristic. Mutation rates can be increased by many different meansincluding temperature, long-term seed storage, tissue cultureconditions, radiation; such as X-rays, Gamma rays (e.g. cobalt 60 orcesium 137), neutrons, (product of nuclear fission by uranium 235 in anatomic reactor), Beta radiation (emitted from radioisotopes such asphosphorus 32 or carbon 14), or ultraviolet radiation (preferably from2500 to 2900 nm), or chemical mutagens (such as base analogues(5-bromo-uracil), related compounds (8-ethoxy caffeine), antibiotics(streptonigrin), alkylating agents (sulfur mustards, nitrogen mustards,epoxides, ethylenamines, sulfates, sulfonates, sulfones, lactones),azide, hydroxylamine, nitrous acid, or acridines. Once a desired traitis observed through mutagenesis the trait may then be incorporated intoexisting germplasm by traditional breeding techniques, such asbackcrossing. Details of mutation breeding can be found in “Principlesof Cultivar Development” Fehr, 1993 Macmillan Publishing Company, thedisclosure of which is incorporated herein by reference. In addition,mutations created in other varieties may be used to produce a backcrossconversion of PHBBK that comprises such mutation.

Breeding with Molecular Markers

Molecular markers, which includes markers identified through the use oftechniques such as Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), Simple Sequence Repeats(SSRs) and Single Nucleotide Polymorphisms (SNPs), may be used in plantbreeding methods utilizing PHBBK.

Isozyme Electrophoresis and RFLPs as discussed in Lee, M., “Inbred Linesof Maize and Their Molecular Markers,” The Maize Handbook,(Springer-Verlag, New York, Inc. 1994, at 423-432), have been widelyused to determine genetic composition. Isozyme Electrophoresis has arelatively low number of available markers and a low number of allelicvariants among maize inbreds. RFLPs allow more discrimination becausethey have a higher degree of allelic variation in maize and a largernumber of markers can be found. Both of these methods have been eclipsedby SSRs as discussed in Smith et al., “An evaluation of the utility ofSSR loci as molecular markers in maize (Zea mays L.): comparisons withdata from RFLPs and pedigree”, Theoretical and Applied Genetics (1997)vol. 95 at 163-173 and by Pejic et al., “Comparative analysis of geneticsimilarity among maize inbreds detected by RFLPs, RAPDs, SSRs, andAFLPs,” Theoretical and Applied Genetics (1998) at 1248-1255incorporated herein by reference. SSR technology is more efficient andpractical to use than RFLPs; more marker loci can be routinely used andmore alleles per marker locus can be found using SSRs in comparison toRFLPs. Single Nucleotide Polymorphisms may also be used to identify theunique genetic composition of the invention and progeny varietiesretaining that unique genetic composition. Various molecular markertechniques may be used in combination to enhance overall resolution.

Maize DNA molecular marker linkage maps have been rapidly constructedand widely implemented in genetic studies. One such study is describedin Boppenmaier, et al., “Comparisons among strains of inbreds forRFLPs”, Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, isincorporated herein by reference.

One use of molecular markers is Quantitative Trait Loci (QTL) mapping.QTL mapping is the use of markers, which are known to be closely linkedto alleles that have measurable effects on a quantitative trait.Selection in the breeding process is based upon the accumulation ofmarkers linked to the positive effecting alleles and/or the eliminationof the markers linked to the negative effecting alleles from the plant'sgenome.

Molecular markers can also be used to reduce the number of crosses backto the recurrent parent needed in a backcrossing program. Withbackcrossing, the expected contribution of PHBBK after 2, 3, 4 and 5doses (or 1, 2, 3 and 4 backcrosses) would be 75%, 87.5%, 93.75% and96.875% respectively. Actual genetic contribution may be much higherthan the genetic contribution expected by pedigree, especially ifmolecular markers are used in selection. The use of molecular markers inthe selection process is often called genetic marker enhanced selection.Molecular markers could also be used to confirm and/or determine thepedigree of the progeny variety.

Production of Double Haploids

The production of double haploids can also be used for the developmentof inbreds in the breeding program. For example, an F1 hybrid for whichPHBBK is a parent can be used to produce double haploid plants. Doublehaploids are produced by the doubling of a set of chromosomes (1N) froma heterozygous plant to produce a completely homozygous individual. Forexample, see Wan et al., “Efficient Production of Doubled Haploid PlantsThrough Colchicine Treatment of Anther-Derived Maize Callus”,Theoretical and Applied Genetics, 77:889-892, 1989 and US2003/0005479.This can be advantageous because the process omits the generations ofselfing needed to obtain a homozygous plant from a heterozygous source.

Haploid induction systems have been developed for various plants toproduce haploid tissues, plants and seeds. The haploid induction systemcan produce haploid plants from any genotype by crossing a selectedvariety (as female) with an inducer variety. Such inducer varieties formaize include Stock 6 (Coe, 1959, Am. Nat. 93:381-382; Sharkar and Coe,1966, Genetics 54:453-464) RWS (see world wide web sitewww.uni-hohenheim.de/%7Eipspwww/350b/indexe.html#Project3), KEMS(Deimling, Roeber, and Geiger, 1997, Vortr. Pflanzenzuchtg 38:203-224),or KMS and ZMS (Chalyk, Bylich & Chebotar, 1994, MNL 68:47; Chalyk &Chebotar, 2000, Plant Breeding 119:363-364), and indeterminategametophyte (ig) mutation (Kermicle 1969 Science 166:1422-1424). Thedisclosures of which are incorporated herein by reference.

Methods for obtaining haploid plants are also disclosed in Kobayashi, M.et al., Journ. of Heredity 7(1):9-14, 1980, Pollacsek, M., Agronomie(Paris) 12(3):247-251, 1992; Cho-Un-Haing et al., Journ. of Plant Biol.,1996, 39(3):185-188; Verdoodt, L., et al., Feb. 1998, 96(2):294-300;Genetic Manipulation in Plant Breeding, Proceedings InternationalSymposium Organized by EUCARPIA, Sep. 8-13, 1985, Berlin, Germany;Chalyk et al., 1994, Maize Genet Coop. Newsletter 68:47; Chalyk, S. T.,1999, Maize Genet. Coop. Newsletter 73:53-54; Coe, R. H., 1959, Am. Nat.93:381-382; Deimling, S. et al., 1997, Vortr. Pflanzenzuchtg 38:203-204;Kato, A., 1999, J. Hered. 90:276-280; Lashermes, P. et al., 1988, Theor.Appl. Genet. 76:570-572 and 76:405-410; Tyrnov, V. S. et al., 1984,Dokl. Akad. Nauk. SSSR 276:735-738; Zabirova, E. R. et al., 1996,Kukuruza I Sorgo N4, 17-19; Aman, M. A., 1978, Indian J. Genet PlantBreed 38:452-457; Chalyk S. T., 1994, Euphytica 79:13-18; Chase, S. S.,1952, Agron. J. 44:263-267; Coe, E. H., 1959, Am. Nat. 93:381-382; Coe,E. H., and Sarkar, K. R., 1964 J. Hered. 55:231-233; Greenblatt, I. M.and Bock, M., 1967, J. Hered. 58:9-13; Kato, A., 1990, Maize Genet.Coop. Newsletter 65:109-110; Kato, A., 1997, Sex. Plant Reprod.10:96-100; Nanda, D. K. and Chase, S. S., 1966, Crop Sci. 6:213-215;Sarkar, K. R. and Coe, E. H., 1966, Genetics 54:453-464; Sarkar, K. R.and Coe, E. H., 1971, Crop Sci. 11:543-544; Sarkar, K. R. and Sachan J.K. S., 1972, Indian J. Agric. Sci. 42:781-786; Kermicle J. L., 1969,Mehta Yeshwant, M. R., Genetics and Molecular Biology, September 2000,23(3):617-622; Tahir, M. S. et al. Pakistan Journal of Scientific andIndustrial Research, August 2000, 43(4):258-261; Knox, R. E. et al.Plant Breeding, August 2000, 119(4):289-298; U.S. Pat. No. 5,639,951 andU.S. patent application Ser. No. 10/121,200, the disclosures of whichare incorporated herein by reference.

Thus, an embodiment of this invention is a process for making ahomozygous PHBBK progeny plant substantially similar to PHBBK byproducing or obtaining a seed from the cross of PHBBK and another maizeplant and applying double haploid methods to the F1 seed or F1 plant orto any successive filial generation. Such methods decrease the number ofgenerations required to produce an inbred with similar genetics orcharacteristics to PHBBK. See Bernardo, R. and Kahler, A. L., Theor.Appl. Genet. 102:986-992, 2001.

In particular, a process of making seed substantially retaining themolecular marker profile of maize inbred variety PHBBK is contemplated,such process comprising obtaining or producing F1 hybrid seed for whichmaize inbred variety PHBBK is a parent, inducing double haploids tocreate progeny without the occurrence of meiotic segregation, obtainingthe molecular marker profile of maize inbred variety PHBBK, andselecting progeny that retain the molecular marker profile of PHBBK.

Use of PHBBK in Tissue Culture

This invention is also directed to the use of PHBBK in tissue culture.As used herein, the term “tissue culture” includes plant protoplasts,plant cell tissue culture, cultured microspores, plant calli, plantclumps, and the like. As used herein, phrases such as “growing the seed”or “grown from the seed” include embryo rescue, isolation of cells fromseed for use in tissue culture, as well as traditional growing methods.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322-332 reflectsthat 97% of the plants cultured that produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91% regenerable callus that produced plants. In a further studyin 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988),7:262-265 reports several media additions that enhance regenerability ofcallus of two inbred varieties. Other published reports also indicatedthat “nontraditional” tissues are capable of producing somaticembryogenesis and plant regeneration. K. P. Rao, et al., Maize GeneticsCooperation Newsletter, 60:64-65 (1986), refers to somatic embryogenesisfrom glume callus cultures and B. V. Conger, et al., Plant Cell Reports,6:345-347 (1987) indicates somatic embryogenesis from the tissuecultures of maize leaf segments. Thus, it is clear from the literaturethat the state of the art is such that these methods of obtaining plantsare, and were, “conventional” in the sense that they are routinely usedand have a very high rate of success.

Tissue culture of maize, including tassel/anther culture, is describedin U.S. 2002/0062506A1 and European Patent Application, publicationEP0160,390, each of which are incorporated herein by reference for thispurpose. Maize tissue culture procedures are also described in Green andRhodes, “Plant Regeneration in Tissue Culture of Maize,” Maize forBiological Research (Plant Molecular Biology Association,Charlottesville, Va. 1982, at 367-372) and in Duncan, et al., “TheProduction of Callus Capable of Plant Regeneration from Immature Embryosof Numerous Zea Mays Genotypes,” 165 Planta 322-332 (1985). Thus,another aspect of this invention is to provide cells which upon growthand differentiation produce maize plants having the genotype and/orphysiological and morphological characteristics of inbred variety PHBBK.

INDUSTRIAL APPLICABILITY

Maize is used as human food, livestock feed, and as raw material inindustry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry.

Industrial uses of maize include production of ethanol, maize starch inthe wet-milling industry and maize flour in the dry-milling industry.The industrial applications of maize starch and flour are based onfunctional properties, such as viscosity, film formation, adhesiveproperties, and ability to suspend particles. The maize starch and flourhave application in the paper and textile industries. Other industrialuses include applications in adhesives, building materials, foundrybinders, laundry starches, explosives, oil-well muds, and other miningapplications.

Plant parts other than the grain of maize are also used in industry: forexample, stalks and husks are made into paper and wallboard and cobs areused for fuel and to make charcoal.

The seed of inbred maize variety PHBBK, the plant produced from theinbred seed, the hybrid maize plant produced from the crossing of theinbred, hybrid seed, and various parts of the hybrid maize plant andtransgenic versions of the foregoing, can be utilized for human food,livestock feed, and as a raw material in industry.

REFERENCES

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DEPOSITS

Applicant has made a deposit of at least 2500 seeds of Inbred MaizeVariety PHBBK with the American Type Culture Collection (ATCC),Manassas, Va. 20110 USA, ATCC Deposit No. PTA-7505. The seeds depositedwith the ATCC on Apr. 14, 2006 were taken from the deposit maintained byPioneer Hi-Bred International, Inc., 7250 NW 62^(nd) Avenue, Johnston,Iowa, 50131 since prior to the filing date of this application. Accessto this deposit will be available during the pendency of the applicationto the Commissioner of Patents and Trademarks and persons determined bythe Commissioner to be entitled thereto upon request. Upon allowance ofany claims in the application, the Applicant will make the depositavailable to the public pursuant to 37 C.F.R. §1.808. This deposit ofthe Inbred Maize Variety PHBBK will be maintained in the ATCCdepository, which is a public depository, for a period of 30 years, or 5years after the most recent request, or for the enforceable life of thepatent, whichever is longer, and will be replaced if it becomesnonviable during that period. Additionally, Applicant has or willsatisfy all of the requirements of 37 C.F.R. §§1.801-1.809, includingproviding an indication of the viability of the sample upon deposit.Applicant has no authority to waive any restrictions imposed by law onthe transfer of biological material or its transportation in commerce.Applicant does not waive any infringement of rights granted under thispatent or under the Plant Variety Protection Act (7 USC 2321 et seq.).U.S. Plant Variety Protection of Inbred Maize Variety PHBBK has beenapplied for. Unauthorized seed multiplication prohibited.

TABLE 1 VARIETY DESCRIPTION INFORMATION PHBBK AVG STDEV N 1. TYPE:(Describe intermediate types in comments section) 1 = Sweet, 2 = Dent, 3= Flint, 4 = Flour, 5 = 3 Pop and 6 = Ornamental. Comments: Flint-Dent2. MATURITY: DAYS HEAT UNITS Days H. Units Emergence to 50% of plants insilk 59 1,344 Emergence to 50% of plants in pollen shed 57 1,300 10% to90% pollen shed 2 54 50% Silk to harvest at 25% moisture 3. PLANT: PlantHeight (to tassel tip) (cm) 202.6 13.80 25 Ear Height (to base of topear node) (cm) 69.4 10.04 25 Length of Top Ear Internode (cm) 17.0 1.7625 Average Number of Tillers per Plant 0.0 0.01 5 Average Number of Earsper Stalk 1.0 0.15 5 Anthocyanin of Brace Roots: 1 = Absent, 2 = 2Faint, 3 = Moderate, 4 = Dark 4. LEAF: Width of Ear Node Leaf (cm) 9.00.73 25 Length of Ear Node Leaf (cm) 72.1 4.38 25 Number of Leaves aboveTop Ear 5.9 0.67 25 Leaf Angle: (at anthesis, 2nd leaf above ear to 27.15.15 25 stalk above leaf) (Degrees) * Leaf Color: V. Dark Green Munsell:7.5GY34 Leaf Sheath Pubescence: 1 = none to 9 = like 2 peach fuzz 5.TASSEL: Number of Primary Lateral Branches 9.8 2.76 25 Branch Angle fromCentral Spike 25.5 4.98 25 Tassel Length: (from peduncle node to tasseltip), 56.4 6.88 25 (cm). Pollen Shed: 0 = male sterile, 9 = heavy shed7 * Anther Color: Pale Yellow Munsell: 5Y76 * Glume Color: Red Munsell:10RP38 * Bar Glumes (glume bands): 1 = absent, 2 = 1 present PeduncleLength: (from top leaf node to lower 23.7 2.29 25 florets or branches),(cm). 6a. EAR (Unhusked ear) * Silk color: Red Munsell: 5R46 (3 daysafter silk emergence) * Fresh husk color: Med. Green Munsell: 5GY68 *Dry husk color: White Munsell: 10YR92 (65 days after 50% silking) Earposition at dry husk stage: 1 = upright, 2 = 1 horizontal, 3 = pendantHusk Tightness: (1 = very loose, 9 = very tight) 4 Husk Extension (atharvest): 1 = short(ears 2 exposed), 2 = medium (<8 cm), 3 = long (8-10cm), 4 = v. long (>10 cm) 6b. EAR (Husked ear data) Ear Length (cm):16.7 1.37 25 Ear Diameter at mid-point (mm) 44.4 1.38 25 Ear Weight(gm): 117.4 12.79 25 Number of Kernel Rows: 15.8 1.56 25 Kernel Rows: 1= indistinct, 2 = distinct 2 Row Alignment: 1 = straight, 2 = slightlycurved, 1 3 = spiral Shank Length (cm): 8.9 1.39 25 Ear Taper: 1 =slight cylind., 2 = average, 3 = 3 extreme conic. 7. KERNEL (Dried):Kernel Length (mm): 10.9 0.57 25 Kernel Width (mm): 7.8 0.58 25 KernelThickness (mm): 4.8 0.60 25 Round Kernels (shape grade) (%) 31.9 5.68 5Aleurone Color Pattern: 1 = homozygous, 2 = 1 segregating * AleuroneColor: Yellow Munsell: 10YR814 * Hard Endo. Color: Yellow Munsell:10YR814 Endosperm Type: 3 1 = sweet (su1), 2 = extra sweet (sh2), 3 =normal starch, 4 = high amylose starch, 5 = waxy starch, 6 = highprotein, 7 = high lysine, 8 = super sweet (se), 9 = high oil, 10 = otherWeight per 100 Kernels (unsized sample) (gm): 24.6 1.52 5 8. COB: * CobDiameter at mid-point (mm): 24.1 1.48 25 * Cob Color: Pink Munsell:10R66 9. DISEASE RESISTANCE: (Rate from 1 = most-susceptable to 9 =most-resistant. Leave blank if not tested, leave race or strain optionsblank if polygenic.) A. LEAF BLIGHTS, WILTS, AND LOCAL INFECTIONDISEASES Anthracnose Leaf Blight (Colletotrichum graminicola) 6 CommonRust (Puccinia sorghi) 8 Common Smut (Ustilago maydis) Eyespot(Kabatiella zeae) Goss's Wilt (Clavibacter michiganense spp.nebraskense) 4 Gray Leaf Spot (Cercospora zeae-maydis) HelminthosporiumLeaf Spot (Bipolaris zeicola) Race: 4 Northern Leaf Blight (Exserohilumturcicum) Race: Southern Leaf Blight (Bipolaris maydis) Race: SouthernRust (Puccinia polysora) 7 Stewart's Wilt (Erwinia stewartii) Other(Specify): B. SYSTEMIC DISEASES Corn Lethal Necrosis (MCMV and MDMV) 24Head Smut (Sphacelotheca reiliana) (% infected) Maize Chlorotic DwarfVirus (MDV) Maize Chlorotic Mottle Virus (MCMV) Maize Dwarf Mosaic Virus(MDMV) Sorghum Downy Mildew of Corn (Peronosclerospora sorghi) Other(Specify): C. STALK ROTS 4 Anthracnose Stalk Rot (Colletotrichumgraminicola) Diplodia Stalk Rot (Stenocarpella maydis) Fusarium StalkRot (Fusarium moniliforme) Gibberella Stalk Rot (Gibberella zeae) Other(Specify): D. EAR AND KERNEL ROTS Aspergillus Ear and Kernel Rot(Aspergillus flavus) 6 Diplodia Ear Rot (Stenocarpella maydis) 6Fusarium Ear and Kernel Rot (Fusarium moniliforme) 6 Gibberella Ear Rot(Gibberella zeae) Other (Specify): 10. INSECT RESISTANCE: (Rate from 1 =most-suscept. to 9 = most-resist., leave blank if not tested.) Corn Worm(Helicoverpa zea) Leaf Feeding Silk Feeding Ear Damage Corn Leaf Aphid(Rophalosiphum maydis) Corn Sap Beetle (Capophilus dimidiatus) EuropeanCorn Borer (Ostrinia nubilalis) 1st. Generation (Typically whorl leaffeeding) 7 2nd. Generation (Typically leaf sheath-collar feeding) StalkTunneling cm tunneled/plant Fall armyworm (Spodoptera fruqiperda) LeafFeeding Silk Feeding mg larval wt. Maize Weevil (Sitophilus zeamaize)Northern Rootworm (Diabrotica barberi) Southern Rootworm (Diabroticaundecimpunctata) Southwestern Corn Borer (Diatreaea grandiosella) LeafFeeding Stalk Tunneling cm tunneled/plant Two-spotted Spider Mite(Tetranychus utricae) Western Rootworm (Diabrotica virgifrea virgifrea)Other (Specify): 11. AGRONOMIC TRAITS: 5 Staygreen (at 65 days afteranthesis; rate from 1—worst to 9— excellent) % Dropped Ears (at 65 daysafter anthesis) % Pre-anthesis Brittle Snapping 1% Pre-anthesis RootLodging 6% Post-anthesis Root Lodging (at 65 days after anthesis) %Post-anthesis Stalk Lodging 6,932.0 Kg/ha (Yield at 12-13% grainmoisture) * Munsell Glossy Book of Color, (A standard color reference).Kollmorgen Inst. Corp. New Windsor, NY.

TABLE 2 SSR PROFILE DATA FOR PHBBK. Marker Name Chromosome Location BasePairs BNLG1014 1 82.8 125.2 BNLG1429 1 143.5 190.8 BNLG1127 1 167.5 98BNLG1953 1 170 207.3 BNLG1064 1 201.3 223.1 BNLG439 1 259.1 233.6PHI339017 1 270.6 146.6 BNLG1016 1 291.7 255.1 BNLG1886 1 377.2 142.2BNLG2086 1 401.2 225.6 BNLG1615 1 557.6 233.4 PHI423298 1 721.9 128.4PHI323065 1 777.4 329.8 PHI335539 1 805.3 89.1 BNLG1720 1 834.5 241.1PHI011 1 839.3 228.5 BNLG1331 1 847 122 PHI308707 1 927.4 132.2PHI265454 1 973 218.7 PHI227562 1 1097.4 323.8 PHI064 1 1103 81.1PHI402893 2 3.8 219.3 PHI96100 2 28.1 281.5 BNLG1017 2 65.7 196.3BNLG1909 2 270.7 298 PHI083 2 284.7 126.7 BNLG1831 2 368.8 194.6BNLG1396 2 372.8 166.4 BNLG1141 2 374.9 154.3 PHI127 2 422.7 122.5PHI328189 2 422.7 122.8 PHI251315 2 453.8 125.1 PHI435417 2 520.5 214.6PHI090 2 548.3 139.1 BNLG1940 2 577.6 247.9 BNLG1520 2 605.8 286.7PHI101049 2 712.1 236.1 PHI453121 3 7.5 218.6 PHI404206 3 11 300.7BNLG1523 3 81.5 318.5 BNLG1647 3 103.3 132.1 PHI374118 3 168 223.5BNLG1452 3 190.8 98.3 PHI029 3 192.3 152.4 PHI073 3 229.7 186.4 PHI053 3297.9 192.7 BNLG1951 3 481.6 127.6 BNLG1160 3 491.4 223.5 PHI193225 3791.6 135.1 PHI295450 4 81 188 PHI213984 4 130.1 285.7 BNLG1937 4 232239.4 PHI096 4 232.2 235.5 PHI079 4 254 186.8 BNLG1265 4 268.4 199.4BNLG1755 4 299.9 217.4 PHI438301 4 452.9 209.5 PHI093 4 522.1 281.9PHI314704 4 655 137.5 PHI396160 5 307 302.1 PHI331888 5 324.3 131.2PHI330507 5 389.9 132.3 BNLG1711 5 666.5 179.1 PHI423796 6 72.7 129.7PHI389203 6 269.8 306.7 PHI452693 6 278 124 PHI445613 6 375.8 101.4PHI364545 6 428.4 132.7 PHI299852 6 450.7 121 PHI328175 7 472.9 122.7PHI420701 8 99.6 292.5 PHI100175 8 274.9 145.1 PHI233376 8 609.1 137.5PHI448880 9 536.8 184 PHI059 10 143.5 154.4 PHI323152 10 468.4 141.1BNLG1450 10 483.7 236.3 BNLG1185 10 529.1 153

TABLE 3A PAIRED INBRED COMPARISON REPORT Variety #1: PHBBK Variety #2:PH7BW YIELD GLFSPT YIELD NLFBLT MST BU/A 56# SCORE BU/A 56# SCORE PCTStat ABS ABS % MN ABS ABS Mean1 105.4 5.0 112.3 4.0 23.8 Mean2 101.7 4.1108.9 6.0 18.0 Locs 17 4 17 1 17 Reps 32 5 32 1 32 Diff 3.7 0.9 3.3 −2.0−5.8 Prob 0.289 0.006 0.357 . 0.000 TSTWT FUSERS EGRWTH STWWLT ESTCNTLB/BU SCORE SCORE SCORE COUNT Stat ABS ABS ABS ABS ABS Mean1 57.8 8.16.0 7.0 30.1 Mean2 57.6 7.1 6.3 7.0 28.0 Locs 4 8 31 2 41 Reps 8 8 31 242 Diff 0.2 1.0 −0.2 0.0 2.0 Prob 0.891 0.068 0.165 1.000 0.000 TILLERGDUSHD GDUSLK EARMLD TASBLS PCT GDU GDU SCORE SCORE Stat ABS ABS ABS ABSABS Mean1 0.8 129.9 131.8 4.0 9.0 Mean2 5.0 124.1 125.8 7.0 8.0 Locs 33116 116 1 3 Reps 33 116 116 1 3 Diff 4.2 5.8 6.0 −3.0 1.0 Prob 0.0260.000 0.000 . 0.423 TASSZ PLTHT COMRST EARHT STAGRN SCORE CM SCORE CMSCORE Stat ABS ABS ABS ABS ABS Mean1 5.8 201.4 5.7 80.9 5.5 Mean2 5.8225.5 4.9 96.6 4.1 Locs 103 65 9 34 21 Reps 103 65 10 34 21 Diff 0.0−24.1 0.8 −15.7 1.4 Prob 0.849 0.000 0.023 0.000 0.005 BRTSTK SCTGRNSTLPCN TEXEAR BARPLT % NOT SCORE % NOT SCORE % NOT Stat ABS ABS ABS ABSABS Mean1 94.2 8.4 100.0 2.8 98.2 Mean2 95.2 8.3 100.0 1.5 98.4 Locs 118 1 4 47 Reps 2 18 1 4 49 Diff −1.0 0.2 0.0 1.3 −0.2 Prob . 0.381 .0.015 0.747 LRTLPN CLDTST ERTLPN STKLDG CLDTST % NOT PCT % NOT % NOT PCTStat ABS ABS ABS ABS % MN Mean1 100.0 97.6 98.3 95.3 101.7 Mean2 100.097.2 65.5 66.8 Locs 2 10 4 3 Reps 2 10 5 3 Diff 0.0 0.4 32.8 28.5 Prob1.000 0.758 0.063 0.204

TABLE 3B PAIRED INBRED COMPARISON REPORT Variety #1: PHBBK Variety #2:PH1W0 EGRWTH STWWLT ESTCNT TILLER GDUSHD SCORE SCORE COUNT PCT GDU StatABS ABS ABS ABS ABS Mean1 5.7 7.0 33.3 0.0 128.4 Mean2 5.0 7.0 31.2 0.0126.8 Locs 6 1 6 2 21 Reps 6 1 6 2 21 Diff 0.7 0.0 2.2 0.0 1.7 Prob0.363 . 0.071 1.000 0.019 GDUSLK TASSZ PLTHT COMRST EARHT GDU SCORE CMSCORE CM Stat ABS ABS ABS ABS ABS Mean1 129.5 6.3 212.6 5.3 85.5 Mean2130.3 6.3 211.9 6.0 90.1 Locs 21 20 15 3 7 Reps 21 20 15 3 7 Diff −0.90.0 0.7 −0.7 −4.7 Prob 0.162 1.000 0.838 0.184 0.272 STAGRN SCTGRNBARPLT STKLDG HSKCVR SCORE SCORE % NOT % NOT SCORE Stat ABS ABS ABS ABSABS Mean1 5.8 8.5 97.5 95.5 7.0 Mean2 6.2 7.0 100.0 100.0 7.0 Locs 5 2 61 1 Reps 5 2 6 1 1 Diff −0.4 1.5 −2.5 −4.5 0.0 Prob 0.477 0.205 0.182 ..

TABLE 4 GENERAL COMBINING ABILITY REPORT FOR PHBBK PRM Day ABS Mean 103PRM Day ABS Reps 3090 PRMSHD Day ABS Mean 102 PRMSHD Day ABS Reps 3090YIELD bu/a 56# ABS Mean 188.5 YIELD bu/a 56# ABS Reps 1712 YIELD bu/a56# ABS Years 4 YIELD bu/a 56# % MN Mean 102.4 YIELD bu/a 56# % MN Reps1712 MST pct ABS Mean 23.4 MST pct ABS Reps 1721 MST pct % MN Mean 103.4MST pct % MN Reps 1721 YLDMST ABS Mean 98.4 YLDMST ABS Reps 1415 STLPCN% NOT % MN Mean 99 STLPCN % NOT % MN Reps 280 STLLPN % NOT % MN Mean 99STLLPN % NOT % MN Reps 369 ERTLPN % NOT % MN Mean 101 ERTLPN % NOT % MNReps 131 LRTLPN % NOT % MN Mean 101 LRTLPN % NOT % MN Reps 246 TSTWTlb/bu % MN Mean 100.1 TSTWT lb/bu % MN Reps 974 STKCNT count % MN Mean100 STKCNT count % MN Reps 2803 PLTHT in % MN Mean 102 PLTHT in % MNReps 547 EARHT in % MN Mean 102 EARHT in % MN Reps 543 BRTSTK % NOT % MNMean 102 BRTSTK % NOT % MN Reps 99 GLFSPT score ABS Mean 5 GLFSPT scoreABS Reps 87 STAGRN score ABS Mean 5 STAGRN score ABS Reps 416 HSKCVRscore ABS Mean 7 HSKCVR score ABS Reps 53 ECBLSI score ABS Mean 5 ECBLSIscore ABS Reps 8

TABLE 5A INBREDS IN HYBRID COMBINATION REPORT Variety #1: HYBRIDCONTAINING PHBBK Variety #2: X5M876 YIELD GLFSPT YIELD NLFBLT MST BU/A56# SCORE BU/A 56# SCORE PCT Stat ABS ABS % MN ABS ABS Mean1 207.1 6.0106.9 6.0 24.7 Mean2 197.2 7.0 101.7 6.0 25.6 Locs 19 1 19 2 19 Reps 192 19 2 19 Diff 9.9 −1.0 5.2 0.0 0.8 Prob 0.013 . 0.014 1.000 0.027 TSTWTSTKCNT GDUSHD GDUSLK PLTHT LB/BU COUNT GDU GDU CM Stat ABS ABS ABS ABSABS Mean1 53.7 56.0 124.5 124.0 293.1 Mean2 54.8 55.8 126.5 120.0 301.0Locs 11 27 4 1 8 Reps 11 34 4 1 8 Diff −1.1 0.2 −2.0 4.0 −7.9 Prob 0.0070.322 0.320 . 0.088 EARHT STAGRN HDSMT STLLPN STLPCN CM SCORE % NOT %NOT % NOT Stat ABS ABS ABS ABS ABS Mean1 127.7 6.2 97.2 81.5 74.3 Mean2123.3 6.7 78.9 96.0 90.0 Locs 8 6 1 3 4 Reps 8 6 1 6 4 Diff 4.4 −0.518.3 −14.5 −15.8 Prob 0.064 0.076 . 0.284 0.364 LRTLPN BRTSTK % NOT %NOT Stat ABS ABS Mean1 91.0 100.0 Mean2 94.3 98.5 Locs 3 1 Reps 3 1 Diff−3.3 1.5 Prob 0.423 .

TABLE 5B INBREDS IN HYBRID COMBINATION REPORT Variety #1: HYBRIDCONTAINING PHBBK Variety #2: X4N127 YIELD YIELD MST TSTWT STKCNT BU/A56# BU/A 56# PCT LB/BU COUNT Stat ABS % MN ABS ABS ABS Mean1 205.8 109.026.0 52.7 60.5 Mean2 187.5 99.2 25.7 53.7 60.4 Locs 24 24 24 15 25 Reps46 46 46 28 48 Diff 18.3 9.8 −0.3 −1.0 0.1 Prob 0.000 0.000 0.327 0.0230.587 GDUSHD GDUSLK PLTHT EARHT STAGRN GDU GDU CM CM SCORE Stat ABS ABSABS ABS ABS Mean1 123.4 124.0 309.5 131.7 5.6 Mean2 122.4 118.5 309.3130.8 5.5 Locs 5 1 7 7 5 Reps 10 2 13 13 10 Diff 1.0 5.5 0.2 0.9 0.1Prob 0.305 . 0.969 0.795 0.749 STLPCN ERTLPN LRTLPN BRTSTK HSKCVR % NOT% NOT % NOT % NOT SCORE Stat ABS ABS ABS ABS ABS Mean1 91.8 100.0 91.0100.0 6.0 Mean2 90.8 87.2 92.2 100.0 7.5 Locs 4 3 3 1 1 Reps 8 5 6 2 2Diff 1.0 12.8 −1.2 0.0 −1.5 Prob 0.878 0.368 0.917 . .

TABLE 6 PHENOTYPIC DATA FROM HYBRIDS PRODUCED WITH PHBBK. PRM PRM YIELDYIELD YIELD PRM PRM SHD SHD bu/a bu/a bu/a Day Day Day Day 56# 56# 56#ABS ABS ABS ABS ABS ABS ABS MEAN REPS MEAN REPS MEAN REPS YRS Hybrid 1102 50 100 50 208 36 2 Hybrid 2 198.5 16 1 Hybrid 3 105 353 105 353186.3 186 3 Hybrid 4 175.3 16 1 Hybrid 5 179.6 16 1 Hybrid 6 101 51 10152 191.2 29 2 Hybrid 7 101 50 99 50 201.3 38 2 Hybrid 8 102 77 96 77199.9 50 2 Hybrid 9 105 40 102 40 186.3 29 2 YIELD YIELD MST YLD bu/abu/a MST MST MST pct MST 56# 56# pct pct pct % Value % MN % MN ABS ABS %MN MN ABS MEAN REPS MEAN REPS MEAN REPS MEAN Hybrid 1 105.8 36 23.3 36104.1 36 101.7 Hybrid 2 101.2 16 22.8 16 104.8 16 96.4 Hybrid 3 100.2186 22.2 187 103.3 187 96.9 Hybrid 4 89.7 16 21.8 16 100.4 16 89.3Hybrid 5 91.8 16 22.4 16 102.9 16 89 Hybrid 6 101.9 29 20.7 29 97.7 29104.1 Hybrid 7 103.1 38 22.7 38 100.2 38 102.9 Hybrid 8 104.1 50 22.7 50103.7 50 100.5 Hybrid 9 105 29 21.1 29 104.3 29 100.6 YLD STL STL STLSTL ERT MST PCN PCN LPN LPN LPN Value % NOT % NOT % NOT % NOT % NOT ABS% MN % MN % MN % MN % MN REPS MEAN REPS MEAN REPS MEAN Hybrid 1 36 73 7101 Hybrid 2 16 96 2 82 Hybrid 3 190 108 14 110 40 101 Hybrid 4 16 96 2117 Hybrid 5 16 85 2 82 Hybrid 6 29 114 1 89 5 Hybrid 7 38 109 7 83Hybrid 8 50 98 8 104 Hybrid 9 29 95 3 93 9 ERT LRT LRT TST TST STK LPNLPN LPN WT WT CNT % NOT % NOT % NOT lb/bu lb/bu count % MN % MN % MN %MN % MN % MN REPS MEAN REPS MEAN REPS MEAN Hybrid 1 4 102 4 99 21 101Hybrid 2 2 86 6 99.5 16 99 Hybrid 3 3 95 25 101.2 119 101 Hybrid 4 2 1026 100.6 16 101 Hybrid 5 2 104 6 97.9 16 100 Hybrid 6 85 5 101.1 21 99Hybrid 7 4 117 4 98.6 23 100 Hybrid 8 3 96 5 100.3 30 100 Hybrid 9 92 699.8 17 101 STK EAR EAR BRT CNT PLTHT PLTHT HT HT STK count in in in in% NOT % MN % MN % MN % MN % MN % MN REPS MEAN REPS MEAN REPS MEAN Hybrid1 49 101 16 103 16 Hybrid 2 15 101 10 98 10 Hybrid 3 338 100 73 98 73101 Hybrid 4 14 109 10 104 10 Hybrid 5 14 109 10 109 10 Hybrid 6 33 10214 105 14 Hybrid 7 49 101 16 98 16 Hybrid 8 73 100 14 100 14 100 Hybrid9 37 104 14 103 14 BRT BOR BRLP BRLP BRLP BRLP STK BMN BMN NE NE NL %NOT % NOT % NOT % NOT % NOT % NOT % MN % MN % MN % MN % MN % MN REPSMEAN REPS MEAN REPS MEAN Hybrid 1 Hybrid 2 Hybrid 3 9 89 22 Hybrid 4Hybrid 5 Hybrid 6 Hybrid 7 Hybrid 8 1 110 6 Hybrid 9 BRLP GLF GLF STASTA HSK HSK NL SPT SPT GRN GRN CVR CVR % NOT score score score scorescore score % MN ABS ABS ABS ABS ABS ABS REPS MEAN REPS MEAN REPS MEANREPS Hybrid 1 4 3 4 4 Hybrid 2 5 4 Hybrid 3 5 16 6 34 5 7 Hybrid 4 5 4Hybrid 5 5 4 Hybrid 6 4 2 5 10 Hybrid 7 5 3 5 5 5 1 Hybrid 8 4 3 3 4 5 1Hybrid 9 4 3 5 8 ECB ECB LSI LSI score score ABS ABS MEAN REPS Hybrid 1Hybrid 2 Hybrid 3 Hybrid 4 Hybrid 5 Hybrid 6 Hybrid 7 Hybrid 8 Hybrid 9

All publications, patents and patent applications mentioned in thespecification are indicative of the level of those skilled in the art towhich this invention pertains. All such publications, patents and patentapplications are incorporated by reference herein for the purpose citedto the same extent as if each was specifically and individuallyindicated to be incorporated by reference herein.

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding. Asis readily apparent to one skilled in the art, the foregoing are onlysome of the methods and compositions that illustrate the embodiments ofthe foregoing invention. It will be apparent to those of ordinary skillin the art that variations, changes, modifications and alterations maybe applied to the compositions and/or methods described herein withoutdeparting from the true spirit, concept and scope of the invention.

1. Maize inbred variety PHBBK, representative seed of said varietyhaving been deposited under ATCC accession number PTA-7505.
 2. A seed ofthe maize inbred variety of claim
 1. 3. A plant of the maize inbredvariety of claim
 1. 4. A plant part of the maize inbred variety ofclaim
 1. 5. The maize inbred variety of claim 1 comprising at least onelocus conversion, wherein said locus conversion is selected from thegroup consisting of male sterility, site-specific recombination, abioticstress tolerance, altered phosphorus, altered antioxidants, alteredfatty acids, altered essential amino acids, altered carbohydrates,herbicide resistance, insect resistance and disease resistance.
 6. Amaize seed produced by crossing the plant of claim 3 with a differentmaize plant.
 7. A maize plant produced by growing the maize seed ofclaim
 6. 8. A plant part of the maize plant of claim
 7. 9. A process ofproducing a conversion of maize inbred variety PHBBK comprising at leastone new trait, the process comprising: (a) crossing a plant of maizeinbred variety PHBBK, representative seed of which has been depositedunder ATCC Accession Number PTA-7505, with a plant of another maizevariety that comprises at least one new trait to produce progeny seed;(b) harvesting and planting the progeny seed to produce at least oneprogeny plant of a subsequent generation, said progeny plant comprisingthe at least one new trait; (c) crossing the progeny plant with a plantof maize inbred variety PHBBK to produce backcross progeny seed; (d)harvesting and planting the backcross progeny seed to produce at leastone backcross progeny plant; and (e) repeating steps (c) and (d) for atleast three additional generations to produce a converted plant ofinbred variety PHBBK, wherein the converted plant of inbred varietyPHBBK comprises the at least one new trait and otherwise has all of themorphological and physiological characteristics of inbred variety PHBBKlisted in Table 1 as determined at the 5% significance level when grownunder the same environmental conditions.
 10. A converted plant of inbredvariety PHBBK produced by the process of claim
 9. 11. A plant part ofthe plant of claim
 10. 12. A maize seed produced by crossing the plantof claim 10 with a different maize plant.
 13. A maize plant produced bygrowing the maize seed of claim
 12. 14. The maize seed of claim 12,wherein the different maize plant comprises at least one locusconversion.
 15. The plant of claim 10, wherein said at least one newtrait is selected from the group consisting of male sterility,site-specific recombination, abiotic stress tolerance, alteredphosphorus, altered antioxidants, altered fatty acids, altered essentialamino acids, altered carbohydrates, herbicide resistance, insectresistance and disease resistance.
 16. A method for developing a secondmaize plant in a maize plant breeding program comprising applying plantbreeding techniques to a first maize plant, or parts thereof, whereinsaid first maize plant is the maize plant of claim 7, and whereinapplication of said techniques results in development of said secondmaize plant.
 17. The method of claim 16, further comprising producing aninbred maize plant derived from the maize variety PHBBK, the methodfurther comprising the steps of: (a) crossing said second maize plantwith itself or a second plant to produce seed of a subsequentgeneration; (b) harvesting and planting the seed of the subsequentgeneration to produce at least one plant of the subsequent generation;(c) repeating steps (a) and (b) for an additional 2-10 generations toproduce an inbred maize plant derived from maize variety PHBBK.
 18. Theseed of claim 2, further comprising a transgene.
 19. The seed of claim18, wherein the transgene confers a trait selected from the groupconsisting of male sterility, site-specific recombination, abioticstress tolerance, altered phosphorus, altered antioxidants, alteredfatty acids, altered essential amino acids, altered carbohydrates,herbicide resistance, insect resistance and disease resistance.
 20. Theplant of claim 3, further comprising a transgene.
 21. The plant of claim20, wherein the transgene confers a trait selected from the groupconsisting of selected from the group consisting of male sterility,site-specific recombination, abiotic stress tolerance, alteredphosphorus, altered antioxidants, altered fatty acids, altered essentialamino acids, altered carbohydrates, herbicide resistance, insectresistance and disease resistance.